The Animal Parasites of Man (part 4 of 6)

The Animal Parasites of Man (part 4 of 6)

In about a fortnight the larva is fully grown and becomes a pupa. The pupa (fig. 393), which moves in jerky movements, remains in the water, but partakes of no food. In shape it somewhat resembles a tadpole, that is to say, it consists of a bulky anterior portion, on the surface of which the head, with its appendages, is recognizable, and a more slender segmented abdomen. Above, on the thorax, there are two small trumpet-shaped breathing tubes for the conveyance of air to the tracheal system. After three or four days the perfect mosquito hatches out, remains a short time on the surface of the water until its chitinous integument is hardened, and then flies away.

The females that are fertilized in the autumn hibernate in sheltered spots in the open air, or in houses, cellars, under stairs, in stables, barns, etc., and are the progenitors of the first generation of the following year.

In accordance with the climate of a country, or the kind of weather of a year, the conditions in regard to the manner of life and the duration of the development of the mosquito vary. At all events, the life-history of the mosquito elucidates many points relating to malaria which were hitherto not understood.

[The length of the egg, larval and pupal life varies so much that it is not possible to give an account of any value here. Frequently the eggs may incubate in two days, whilst I have had Stegomyia fasciata eggs from Cuba that have hatched out under abnormal circumstances more than two months after they were laid (“Mono. Culicid.,” iii, p. 6). Some larvæ, as Anopheles bifurcatus, live for months during the winter. Some mosquitoes therefore hibernate as larvæ. The larvæ and pupæ of the different genera present very marked characters, mainly in regard to the structure of the siphons. Specific differences may be found in the frontal hairs of Anopheline larvæ and in the number and arrangement of a group of spines at the base of the siphon in Culicines.--F. V. T.]

*Culicidæ or Mosquitoes.*

The importance of these insects to man is very great. They not only produce painful bites, which may become inflamed and give rise to a considerable amount of œdema, but they are more important on account of the part they play in the distribution of various diseases. Culicidæ may not only carry disease germs, but act as intermediate hosts for certain parasites, such as some of the Anophelina for malarial parasites, Culex for Filariæ, and Stegomyia for yellow fever, etc.; the last-named is in any case the distributor of that fatal disease. It is therefore very necessary to know the life-history, habits and characters of these pests.

Mosquitoes exist in almost all parts of the world from the Arctic circle to the tropics; temperate regions suffer from them less than the two extremes, but even there they form not only a source of great annoyance but of danger as malaria and possibly now and again yellow fever carriers. A few years ago comparatively few species were known, now some 800 odd have been described. Their number will probably not stop far short of 1,000, in spite of the fact that many have been described under different names, yet really the same species. Some are purely domestic, others entirely sylvan; the former, as we might expect, often have a very wide distribution, having been taken from place to place in boats and trains. The more rapid transport becomes, the greater becomes the possibility of this wide distribution of many species increasing, and the spread of other species from their natural home to foreign parts by sea and then by trains further inland.

All Culicidæ are aquatic in their larval and pupal stages. Almost all small collections of water, both natural and artificial, may form breeding grounds for these pests. Some even breed in pitcher plants and many in bromelias. The favourite resorts for the larvæ of Anophelina are small natural collections of water, such as puddles, ditches and small pools around swamps; certain species (A. maculipennis, etc.) live in rain barrels as well. They may also occur in the sluggish water at the edges of rivers or even in mid river, where the flow is checked by masses of water weeds (Myzomyia funesta, etc.). The Stegomyias prefer artificial collections of water, but also occur in natural pools. The yellow fever species (S. fasciata) prefers small collections, such as in barrels, pots, jars, etc. Culex occur in all manner of places--rain barrels, tanks, cisterns, ponds and ditches. Some of the South American species of Culex, Wyeomyia, Joblotia, etc., breed in the collections of water at the base of bromelia leaves.[387] Very few Culicid larvæ live in salt water except in Australia, where Dr. Bancroft has found them in salt water of specific gravity 1·040 (Mucidus alternans and Culex annulirostris). Other salt water mosquitoes are known in America. The food of the larvæ is very varied; the majority appear to feed upon confervæ, small crustacea and insects; some are cannibals, readily devouring others of their own kind. The larger larvæ of Megarhinus, Psorophora, Toxorhynchites and Mucidus are extremely ravenous and devour one another.

[387] “Wald Mosquitoes und Wald Malaria,” Dr. Lutz, _Centralbl. f. Bakt., Par., u. Infektionsk._, i Abt. Orig., xxxiii, No. 4.

There are two main types of larvæ, the Anopheline and Culicine; in the former there is no respiratory siphon, in the latter the siphon is long or moderately long. The head offers certain marked peculiarities which are of specific value; this especially applies to the Anophelina, in which the frontal hairs are of great service in distinguishing the larvæ,[388] whilst in Culex the number and position of the spines at the base of and on the siphon are characteristic. The position assumed by the larvæ in the water also varies in the different groups; most of the Anophelines lie horizontally, most of the Culicina and Ædeomyina hang head downwards. The pupæ also vary, but not to the same extent; the chief differences to be noticed are in the form of the two respiratory trumpets.

[388] Information sent me by Dr. Grabham shows this statement to be not quite correct, as the frontal hairs may vary in different stages of the same larva. This he has shown in Cellia albipes, Theob., and I have noticed it in a Nyssorhynchus from Africa.

The eggs, which may be laid separately (Anopheles maculipennis, Stegomyia fasciata, Joblotia nivipes, etc.), or in rafts (Culex pipiens, C. fatigans) or in chains (Pseudotæniorhynchus fasciolatus), present a great variety of forms. The most peculiar are shown in fig. 395 (Tæniorhynchus, Culex, Stegomyia, Anopheles, Psorophora).

As in all insects, they differ very materially in each species of one genus. Those best known are the Anopheline eggs.

The eggs always float on the surface of the water; immersion soon destroys them, but many may occur in mud and can resist desiccation.

Characters of Adult Culicidæ.--The chief characters by which true mosquitoes, or Culicidæ, are known are the following:--

(1) Wings always with the veins covered with scales; the longitudinal veins, usually six in number (in one genus seven); the costal vein carried round the border of the wing.

(2) Head, thorax and abdomen usually, but not always (Anopheles, etc.), covered with scales.

(3) Mouth parts formed into a long piercing proboscis.

As a rule the males may be told from the females by their antennæ being plumose, whilst in the females they are pilose (vide fig. 394), but this does not invariably hold good, for in Deinocerites, Theobald, and Sabethes, Desvoidy, and others, they are pilose in both sexes. The labial palpi are very variable in regard to their form and the number of segments; in the Anophelina they are long in both sexes, as long or nearly so as the proboscis, more or less clubbed in the males; in Culicina, Joblotina and Heptaphlebomyia, they are long in the males, short in the females; in Ædeomyina, short in both sexes.

Scales.--The most important structural peculiarities in Culicidæ are the scales, which form the chief and most readily observed characters for separating genera and species. The importance of scale structure has been recently ignored by some workers, who are probably right academically, but as a means of separating groups, and so more easily running down a species, the practical man is strongly advised to follow this method. As to what a genus is, is purely a matter of personal opinion. If one examines any recent standard work on entomology one will find a species being placed in varied genera by the varied authorities.

The head, thorax, abdomen and wings are in nearly all cases clothed with squamæ of varied form, of which the following are the main types (fig. 397):--

(1) Flat, spade-shaped scales (a). (2) Narrow curved scales (e). (3) Hair-like curved scales (d). (4) Spindle-shaped scales (f). (5) Small spindle-shaped scales (g). (6) Upright forked scales (h) and (i). (7) Twisted upright scales (j). (8) Inflated or pyriform scales (k). (9) Mansonia scales (b). (10) Small broad asymmetrical scales (c).

Various other varieties are found on the wings, such as:-- (1) Narrow linear lateral scales. (2) Narrow lanceolate scales. (3) Broad lanceolate scales. (4) Elongated, broad, truncated scales (= Pseudotæniorhynchus-like scales). (5) Pyriform scales. (6) Asymmetrical broad or Tæniorhynchus scales. (7) Flat spade-like scales.[389]

[389] Heart-shaped scales occur on the wings of Etiorleptiomyia.

The wings have a series of scales along the middle line of the veins, and also lateral scales to all or nearly all the veins. The wing is also fringed by a series of scales (fig. 396), which, however, are of little systematic importance; the so-called “border scales” (b.s.) vary, however, to some extent, and are useful characters in separating some of the Tæniorhynchus.

THE CLASSIFICATION OF Culicidæ.

SECTION A.--Proboscis formed for piercing; metanotum nude. Scutellum simple. I. Wings with six-scaled longitudinal veins. A. Palpi long in the male. α. Palpi long in both sexes, clavate in ♂ Anophelina. I. First submarginal cell as long or longer than the second posterior cell. Antennal segments without dense lateral scale tufts.

{ {Wing scales { { lanceolate Anopheles, Meigen. { {Wing scales { { mostly long { { and narrow Myzomyia, Blanchard. {Prothoracic {Wing scales { lobes { as above, { simple; no { but fourth { flat head { long vein Thorax and { scales { near base abdomen { { of third and Neomyzomyia, Theobald. with hair- { { outstanding like scales{ { scales on { { prothoracic { { lobe { {Wing scales { { partly large { { and inflated Cycloleppteron, Theobald. { Prothoracic lobes mammil- { lated; some flat head { scales. Basal lobe of ♂ { genitalia of two segments Stethomyia, Theobald. Prothoracic lobes with dense outstanding scales Feltinella, Theobald. Thorax with some narrow curved scales; abdomen hairy Pyretophorus, Blanchard. Wing scales small and lanceolate. Wing scales broad and lanceolate Myzorhynchella, Theobald. Thorax with hair-like curved scales, some narrow curved ones in front; abdomen with apical lateral scale tufts, scaly venter; no ventral tuft Arribalzagia, Theobald. Thorax with hair-like curved scales; abdominal scales on venter only, with a distinct ventral apical tuft Myzorhynchus, Blanchard. Much as above, but abdomen with long spine-like dense lateral tufts Chrystia, Theobald. Thorax with very long hair-like curved scales; abdomen pilose, except last two segments which are scaly; dense scale tufts on third femora; wings with broadish, blunt, lanceolate scales Lophoscelomyia, Theobald. {Abdominal scales as { lateral dorsal patches { of small flat scales; Thorax and { thoracic scales narrow abdomen { and curved, or spindle- { shaped Nyssorhynchus, Blanchard. with scales {Abdomen nearly completely { covered with irregular { scales and with lateral Cellia, Theobald. { tufts {No lateral scale tufts Neocellia, Theobald. Thoracic scales hair-like except a few narrow curved ones in front; abdominal scales long, broad and irregular Kerteszia, Theobald. Thorax with hair-like curved scales and some broad straight scales, others spatulate on sides. Abdomen covered with fine hairs except last three segments, which are scaly. Tufts of scales on hind femora. Wing scales lanceolate Manguinhosia, Cruz. Antennal segments with many dense scaly tufts Chagasia, Cruz. Antennæ with outstanding scales on second segment, more appressed ones on the first. At least one segment of abdomen with long flat more or less spatulate scales Calvertina, Ludlow.

II. First submarginal cell very small Bironella, Theobald. With a distinct cylindrical tubercle projecting obliquely from the prothoracic region Dactylomyia, Newstead and Carter.[390] Scutellum trilobed. First submarginal cell much smaller than the second posterior cell; proboscis long and bent Megarhininæ. Palpi long in both sexes Megarhinus, Rob. Desvoidy. Last segment of ♂ palpi blunt. Last segment of ♂ palpi long and pointed Ankylorhynchus, Lutz.

[390] The following genera of Anophelites have been founded by James†:--

† Records of Indian Museum, 1910, iv, No. 5, p. 98.

(1) Abdomen with hairs but no scales. Thorax with dorsum with long narrow curved scales, which form on the anterior promontory a thick bunch projecting over the neck. Prothoracic lobes with a tuft of rather broad true scales, upright forked scales of head of usual broad expanding type: Patagiamyia, James. Includes Gigas, Giles, and Lindesayi, Giles. Both seem to me typical Anopheles.

(2) Abdomen as above; Thorax very similar. Prothoracic lobes with hairs, no scales. Upright forked scales of head rod-shaped: Neostethopheles, James. Includes Atkenii, James; Immaculatus, Theobald; Culiciformis, James and Liston. These seem to me to be true Anopheles.

(3) Abdomen with hairs and scales on dorsum of each segment; ventrally there are six scaly tufts on the apices of six segments. Thorax with scales and a tuft of outstanding ones on prothoracic lobes: Christophersia, James. Type Halli, James. Very close to if not identical with Cellia.

(4) Head with narrow curved scales lying rather flat upon head and flat lateral scales, upright forked ones behind. Central lobe of scutellum with tuft of narrow curved scales, lateral lobes with large flat oval scales; male palpi longer than proboscis, two large apical segments with long projecting hairs: Leslieomyia, Christophers. Type Leslieomyia tæniorhynchoides, Christophers, from Amritsar, India.

(5) Abdomen with first six or seven segments with hairs only, eighth and seventh (?) with scales, also genital processes. Thorax with hairs and narrow curved scales sharp pointed, blunt-ended broad scales on each side of anterior third. No tufts of scales on prothoracic lobes. Head usual type of upright forked scales: Nyssomyzomyia, James. Type Rossii, Giles.

β. Palpi short in the female Toxorhynchites, Theobald. First submarginal cell longer than the second posterior cell Culicinæ. Legs more or less densely scaly; head not entirely clothed with flat scales; all the legs densely scaly. Wings with large pyriform scales Janthinosoma, Arribalzaga. Head entirely clothed with flat scales. Legs uniformly scaled with flat scales. Head and scutellar scales all flat and broad. Palpi of ♀ short, of ♂ thickened apically and tufted Stegomyia, Theobald. Palpi of ♀ longer than in Stegomyia and in ♂ long and thin, acuminate, simple Desvoidea, Blanchard. Head scales mostly flat, but a median line of narrow curved ones; scutellar scales flat on mid lobe, narrow curved on lateral lobes and palpi longer than proboscis Macleayia, Theobald. Head scales mostly flat, irregular, narrow curved ones behind; mid lobe scutellum with flat scales, lateral with narrow curved; ♂ palpi shorter than proboscis Catageiomyia, Theobald. Head scales mostly flat, but a few narrow curved ones in middle in front; scutellar scales all flat Scutomyia, Theobald. Head scales all flat; scutellar scales all narrow curved Skusea, Theobald. Head with flat scales, except a small median area of narrow curved ones; scutellar scales all narrow curved Howardina, Theobald. Head with all flat scales except a thin line of narrow curved ones behind; scutellar scales all narrow curved Danielsia, Theobald. Head with small flat scales over most of surface, with median line and line around eyes of narrow curved ones; scutellar scales bluntly spindle or club-shaped Hulecoetomyia, Theobald. Head and scutellar scales narrow curved. Wing scales long, narrowly lanceolate, collected in spots; palpi clubbed in ♂; five-jointed and rather long in ♀ Theobaldia, Neveu-Lemaire. Wing scales (lateral) long and narrow, and ♀ palpi three-jointed, ♂ not clubbed and hairy Culex, Linnæus. Wing scales at apex of veins dense and rather broad, femora swollen; small dark species Melanoconion, Theobald. Wings with short, thick, median scales and short, broadish lateral ones on some of the veins; scales mottled; fork-cells rather short Grabhamia, Theobald. Wings with dense, broadish, elongated, truncated scales Pseudotæniorhynchus, Theobald. Wings with broad, short, asymmetrical scales Tæniorhynchus, Arribalzaga. Head covered with rather broad, flat, spindle-shaped scales; scutellum with small flat scales to mid lobe Gilesia, Theobald. Head clothed with flat, irregularly disposed scales all over, with patches of narrow curved ones; ♂ palpi clubbed Acartomyia, Theobald. Abdomen with projecting flat lateral scales with deeply dentate apices; wings not ornamented Lasioconops, Theobald. Wings ornamented; scutellum with flat and narrow curved scales Finlaya, Theobald.

γ. Palpi short in ♂ and ♀ Ædeomyina. Wings unornamented. Antennæ pilose in ♂ and ♀; second joint very long Deinocerites, Theobald. Antennæ plumose in the ♂. Head clothed with narrow curved and flat scales. Mid-lobe of scutellum with six border- bristles. Scutellum with narrow curved scales. Palpi in ♀ four-jointed, in ♂ two- jointed Ædes, Meigen. Mid-lobe of scutellum with four border bristles. Scutellum with flat scales. Head clothed with flat scales only. Fork-cells normal length. Mid-lobe of scutellum with four border- bristles. Palpi of ♀ two-jointed Verallina, Theobald. Palpi of ♀ five-jointed, metallic Hæmagogus, Williston. Fork cells very small or small. Scutellar scales flat. First submarginal cell longer than the second posterior cell; no flat scales on mesothorax Ficalbia, Theobald. First submarginal cell smaller than the second posterior cell; flat scales on mesothorax Uranotænia, Arribalzaga. Scutellar scales narrow curved. First submarginal cell as in Uranotænia Mimomyia, Theobald. Wings ornamented with Mansonia-like scales Ædeomyia, Theobald.

SECTION B.--Metanotum ornamented with chætæ, squamæ or both. α. With chætæ only. Proboscis longer than whole body; lateral wing scales Tæniorhynchus-like Phoniomyia, Theobald. Proboscis as long as whole body in ♀ } frons drawn out into a prominence; } Binotia, Blanchard = wing scales rather broad and long } Runchiomyia, Theobald. Proboscis not as long as the whole body; lateral vein scales narrow Wyeomyia, Theobald. Proboscis not as long as whole body, swollen apically; wing scales long and broad Dendriomyia, Theobald.

β. Metanotum with squamæ and chætæ. Palpi short in ♂ and ♀. Proboscis straight in ♀ and ♂; legs with scaly paddles Sabethes, Rob. Desvoidy. Venation like Sabethes. Legs simple Sabethoides, Theobald. Venation like Culex Goeldia, Theobald. Proboscis in ♂ elbowed, with two scaly tufts Limatus, Theobald. Palpi long in ♂, short in ♀ Joblotina, Blanchard.

II. Wings with seven-scaled longitudinal veins: Culex type Heptaphlebomyia, Theobald.

SECTION C.--Proboscis short, not formed for piercing Corethrina. Metatarsus longer than first tarsal joint Corethra, Linnæus. Metatarsus shorter than first tarsal joint Mochlonyx, Ruthe.[391]

[391] Many other genera have been created; these will be found in my catalogue of Culicidæ in my “Monograph of the Mosquitoes of the World,” 1901–10, 5 vols., in my “Novæ Culicidæ,” family Culicidæ, Genera Insectorum, etc.

NOTES ON THE DIFFERENT GENERA.

Sub-family. *Anophelina.*

The following Anophelines have been recorded as malaria carriers:--

*Anopheles maculipennis, Meigen. Anopheles bifurcatus, Linnæus. *Myzomyia funesta, Giles. Myzomyia lutzii, Theobald. *Myzomyia rossii, Giles. Myzomyia listonii, Liston. Myzomyia culicifacies, Giles. Pyretophorus superpictus, Grassi. *Pyretophorus costalis, Loew. Pyretophorus chaudoyei, Theobald. *Cellia argyrotarsis, Robineau Desvoidy. Myzorhynchus pseudopictus, Grassi. Myzorhynchus barbirostris, Van der Wulp. Myzorhynchus sinensis, Wiedemann. Myzorhynchus paludis, Theobald. Myzorhynchus mauritianus, Grandpré. Neocellia stephensii, Liston. Neocellia willmori, James. Nyssorhynchus theobaldii, Giles. Nyssorhynchus fuliginosus, Giles. Nyssorhynchus annulipes, Walker.

Those marked with an asterisk (*) also carry the larvæ of Filaria bancrofti, as also do Myzorhynchus minutus, Theobald, and Myzorhynchus nigerrimus, Giles.

Genus. *Anopheles*, Meigen.

“Syst. Beschr. Europ. zwei. Ins. I,” 1818, ii, p. 2, Meigen; “Mono. Culicid.,” 1903, i, p. 191; iii, p. 17; and 1910, v, p. 3, Theobald.

This genus contains a few large species found either in temperate climates or in hills and mountains of warm climates. The type is the European and North American A. maculipennis.

A. maculipennis, Meigen. This species and A. bifurcatus are malaria carriers. True Anopheles only occur in Europe, North America, the North of Africa and in the mountains of India, and one has been found by Bancroft similar to A. bifurcatus in Queensland. They are easily told by the absence of scales on thorax and abdomen, and by the rather densely scaled wings with lanceolate scales.

Genus. *Myzomyia*, Blanchard; *Grassia*, Theobald.

Comp. rend. heb. Soc. Biol., No. 23, p. 795, Blanchard; “Mono. Culicid.,” 1910, iii, p. 24; v, p. 16, Theobald.

This genus occurs in Asia, Africa and South America, Europe and East Indies. The type is M. funesta, Giles, found in Central and West Africa. Although structurally there is not much difference between this genus and Anopheles, they differ greatly in appearance, and there are usually a few narrow curved thoracic scales projecting over the head, whilst the wing scales are much smaller in proportion, and the wings more uniformly spotted, always so along the costa. Funesta and lutzii are undoubtedly malaria bearers and also rossii.

Genus. *Neomyzomyia*, Theobald.

“Mono. Culicid.,” 1910, v, p. 29.

A single species only occurs in this genus, N. elegans, James, from India. In this genus, which is near to Myzomyia, the fourth long vein is very near the base of the third, and there are outstanding scales on the prothoracic lobes, and there is a marked tuft of dense scales at the posterior angles of the head.

Genus. *Cycloleppteron*, Theobald.

“Mono. Culicid.,” 1903, ii, p. 312; 1903, iii, p. 58; 1910, v, p. 33.

Two common species only occur in this genus, C. grabhamii, Theob., from Jamaica, and C. mediopunctatus, Theob. (Lutz., ms.), from South America. The chief character is the presence of large black inflated pyriform scales on the wings. The palpi are densely scaled. Neither have been shown to be malaria bearers.

Genus. *Feltinella*, Theobald.

“Mono. Culicid.,” 1907, iv, p. 56.

A single species, so far only found in this genus. The basal lobes of the male genitalia of two segments, the prothoracic lobes with dense outstanding scales.

The species, F. pallidopalpi, Theob., occurs in Sierra Leone.

Genus. *Stethomyia*, Theobald.

“Mono. Culicid.,” 1903, iii, p. 13; 1907, iv, p. 59; 1910, v, p. 35.

Four species occur in this marked genus--one S. nimba, Theob., from British Guiana and Para, another S. fragalis, Theob., from the Malay States, S. culiciformis, James and Liston, from India, and S. pallida, Ludlow, from India.

The former may be a malaria carrier, for Dr. Low says: “Malarial fever is got amongst the Indians and often of a severe type. In that connection it is interesting that in the interior, at a place called Corato, I got an entirely new Anopheles in large numbers.” The genus is easily told by its unornamented wings, flat head scales, mammillated prothoracic lobes and long thin legs.

Genus. *Pyretophorus*, Blanchard; *Howardia*, Theobald.

Compt. rend. heb. Soc. Biol., No. 23, p. 705, Blanchard; Journ. Trop. Med., v, p. 181; and “Mono. Culicid.,” 1903, iii, p. 13; 1910, v, p. 36, Theobald.

Forty-four species come in this genus, of which Anopheles costalis, Loew, is the type.

This genus is found in Africa, India, Europe and in Australia. Three species are proved malaria bearers, namely, P. costalis, Loew, P. chaudoyei, Theob., and P. superpictus, Grassi. Members of this genus can be told by having narrow curved thoracic scales, hairy abdomen, and much-spotted wings.

Genus. *Myzorhynchella*, Theobald.

“Mono. Culicid.,” 1907, iv, p. 78.

In this genus the thorax has distinct, narrow curved scales, and the abdomen is hairy, the wing scales broad and lanceolate, and the head with broad scales not closely appressed, but not forked or fimbriated.

Five species are known: lutzi, Cruz; parva, Chagas; nigritarsis, Chagas; tibiomaculata, Neiva; gilesi, Neiva; and nigra, Theobald. They are all recorded from Brazil, and nigra also from Mexico.

Genus. *Manguinhosia*, Cruz, in Peryassu.

“Os Culicideos do Brazil,” 1908, p. 112.

A single marked species from the Brazils. The thorax has piliform curved scales, and some narrow curved and flattened ones on the sides. Abdomen pilose, except the last three segments which are scaled. No tufts of scales on posterior femora.

Allied to Lophoscelomyia, but at once told by the absence of scale tufts on the hind femora. M. lutzi, Cruz, Brazil.

Genus. *Chrystya*, Theobald.

“Rep. Sleeping Sickness, Roy. Soc. Eng.,” 1903, vii, p. 34.

A very marked genus in which the hairy abdomen has very long, dense, hair-like, apical, scaly tufts to the segments. A single species only so far known, C. implexa, Theobald, from Africa (Uganda, Sudan, etc.).

Genus. *Lophoscelomyia*, Theobald.

Entomologist, 1904, xxxvi, p. 12.

A single species only, from the Federated Malay States. The hind femora have dense, apical scale tufts; the thorax long, hair-like curved scales; abdomen pilose, except the last two segments which are scaly; wings with broad, blunt, lanceolate scales.

Genus. *Arribalzagia*, Theobald.

“Mono. Culicid.,” 1903, iii, pp. 13 and 81; and 1910, v, p. 48.

Two species only occur, found in South America. The thorax and abdomen have scales and hairs respectively, as in Pyretophorus, but the abdomen has in addition prominent lateral apical scale tufts to the segments and a scaly venter. Wings with membrane tinged in patches and wing scales bluntly lanceolate and very dense. The type is A. maculipes, Theob. found in Trinidad and Brazil; A. pseudomaculipes, Cruz, also in Brazil.

Genus. *Myzorhynchus*, Blanchard; *Rossia*, Theobald.

Compt. rend. heb. Soc. Biol., 1902, No. 23, p. 795, Blanchard; Journ. Trop. Med., 1902, p. 181, Theobald; “Mono. Culicid.,” 1903, iii, p. 84; 1907, iv, p. 80; 1910, v, p. 49.

A very marked genus of large, dark, densely scaled species, found in Europe, Asia, Africa and Australia. The thorax with hair-like curved scales; the abdomen with ventral and apical scales, and a median ventral apical tuft, and with very densely scaled palpi in the female, and densely scaled proboscis. It seems to be mainly an Asiatic and East Indian genus, but three species occur in Africa and one in Australia. They are mostly sylvan species and bite severely.

Fourteen species are known. Five are malaria carriers (vide list, p. 566).

Genus. *Nyssorhynchus*, Blanchard; *Laverania*, Theobald.

“Mono. Culicid.,” 1910, iii, p. 14; v, p. 55, Theobald; Compt. rend. heb. Soc. Biol., No. 23, p. 795, Blanchard.

A group of small, closely allied species found in Asia, Africa and Australia, twelve out of the twenty species coming from India.

The thorax is covered with narrow curved and spindle-shaped scales, abdomen with small, flat or narrow curved dorsal scales, especially on the apical segments or in patches; the legs are always banded or spotted with white, and the tarsi have as a rule one or more pure white segments. (This banding and spotting is of no generic value, however.)

The species show considerable seasonal variation. The type of the genus is N. maculatus, Theobald.

Three are malaria carriers (vide list, p. 566).

Genus. *Cellia*, Theobald.

“Mono. Culicid.,” 1903, iii, p. 107; 1910, v, p. 67.

Very marked Anophelines, with densely scaly abdomens, the scales irregularly disposed on the dorsum and forming dense lateral tufts; thorax with flat spindle-shaped scales; palpi densely scaled and also the wings.

The type of the genus is the African C. pharoensis, Theob. It is represented in Asia by C. kochii, Dönitz; in West Indies and South America by C. argyrotarsis, Desvoidy, and C. bigotii, Theob.; in Africa by C. squamosa, Theob., etc.

C. argyrotarsis, Desvoidy, and C. albimana, Wiedemann, are undoubtedly malaria bearers.

Genus. *Neocellia*, Theobald.

“Mono. Culicid.,” 1907, iv, p. 111.

Allied to Cellia, but has no lateral scale tufts. Three species recorded from India.

Genus. *Kertészia*, Theobald.

“Ann. Mus. Nat., Hung.,” 1905, iii, p. 66.

This genus has the thoracic scales hair-like, except a few narrow curved ones in front; abdominal scales long, broad and irregular.

A single species, K. boliviensis, Theob. from Bolivia.

Genus. *Manguinhosia*, Cruz.

The thorax has narrow hair-like curved scales and some broad straight scales; others spatulate on the sides. Abdomen with fine hairs, except the last three segments which are scaly. Tufts of scales on the hind femora. Wing scales lanceolate.

The type is M. lutzi, Cruz, from Brazil.

Genus. *Chagasia*, Cruz.

“Brazil-Medico,” 1906, xx, pp. 20, 199.

This genus can at once be told by the antennal segments having many dense scaly tufts. Type, C. fajardoi, Lutz, from Brazil.

Genus. *Calvertina*, Ludlow.

Canadian Entomologist, 1909, xli, pp. 22, 234.

The antennæ in this genus have outstanding scales on the second segment, more appressed ones on the first. At least one abdominal segment with long, flat, more or less spatulate scales. Type, C. lineata, Ludlow, from Philippine Islands.

Genus. *Birónella*, Theobald.

“Ann. Mus. Nat. Hung.,” 1905, iii, p. 69.

At once told by the first submarginal cell being very small. Type, B. gracilis, Theob. from New Guinea.

Sub-family. *Megarhininæ.*

Three genera occur in this marked sub-family; they are the largest of all mosquitoes, and are very brilliantly coloured, and many have tail fans. They occur in North and South America, Asia, Africa, and Australia. The long curved proboscis is very marked. They are usually spoken of as elephant mosquitoes; some are vicious blood-suckers at times.

The three genera tabulate as follows:--

α. Palpi long in both sexes. β. Last segment of ♀ palp round or blunt as if broken Genus Megarhinus, R. Desvoidy. ββ. Last segment of ♀ palp long and pointed Genus Ankylorhynchus, Lutz. αα. Palpi of female short of male long. Palpi of female not more than one-third length of proboscis Genus Toxorhynchites, Theobald.

Genus. *Megarhinus*, Robineau Desvoidy.

“Mém. Soc. d’Hist. nat. de Paris,” 1827, iii, p. 412; “Mono. Culicid.,” 1901, i, p. 215; 1903, iv, p. 163; 1907, iv, p. 128; 1910, v, p. 89.

All large brilliant mosquitoes with long palpi in both sexes and, as a rule, with a caudal fan of scales; the proboscis is long and bent. They are all sylvan species, and are not so far recorded as biting man.

Genus. *Toxorhynchites*, Theobald.

“Mono. Culicid.,” 1901, i, p. 244; 1903, iii, p. 119; 1907, iv, p. 140; 1910, v, p. 95.

Differs from the former genus in that the female palpi are short. The palpi may have one, two or three minute terminal segments. Banks’s genus Worcesteria has three.

The elephant mosquito of India (T. immisericors), Walker, bites very severely. They are sylvan species.

Sub-family. *Culicinæ*.

Genus. *Mucidus*, Theobald.

“Mono. Culicid.,” 1901, i, p. 268; 1910, v, p. 125.

This genus is so far confined to Australia, West and Central Africa, India, East Indies and Malay Peninsula. They are all large mosquitoes, easily told by the whole body being more or less covered with long twisted scales, giving them a mouldy appearance, and the legs densely scaled with outstanding scales; the wings with large parti-coloured scales. The Australian M. alternans, Walker, occurs in larval form both in fresh and salt water. The adults bite man.

Genus. *Psorophora*, Robineau Desvoidy.

“Mém. de la Soc. d’Hist. nat. de Paris,” 1827, iii, p. 412, R. Desvoidy; “Mono. Culicid.,” 1901, i, p. 259; 1903, iii, p. 130; 1907, iv, p. 158; 1910, v, p. 123, Theobald.

This genus is confined to the Americas and the West Indies. Several species exist which can easily be told from Mucidus by the absence of long twisted scales and the narrower wing scales. The legs are densely scaled and the thorax ornamented with flat spindle-shaped scales.

P. ciliata, Robineau Desvoidy, occurs in both North and South America, and bites man.

Genus. *Janthinosoma*, Arribalzaga.

“Dipt. Arg.,” 1891, p. 52, Arribalzaga; “Mono. Culicid.,” 1901, i, p. 253; 1903, iii, p. 124; 1907, iv, p. 152; and 1910, v, p. 118, Theobald.

Hind legs only densely scaled; some of the hind tarsi are always white. The venation is as in Culex. The abdomen is metallic and iridescent. They all bite man and occur only in the Americas and West Indies.

Genus. *Stegomyia*, Theobald.

“Mono. Culicid.,” 1901, i, p. 283; 1903, iii, p. 130; 1907, iv, p. 170; 1910, v, p. 151.

This, the most important genus in the Culicinæ, can be told by the head and scutellum being clothed with flat scales and the thorax with narrow curved ones.

About forty species are known in this genus, occurring in Southern Europe, Asia, Africa, Australia, the Americas, East and West Indies, and on most oceanic islands. Many of them seem to be vicious blood-suckers. They are mostly black and white mosquitoes, and several seem to go by the name of tiger mosquitoes. The genus contains the yellow fever mosquito (S. fasciata, Fabricius), the only one that need be dealt with in detail here. The chief known species tabulate as follows:--

A. Proboscis banded. α. Legs basally banded. Thorax brown, with scattered creamy- white scales annulirostris, Theobald. Thorax black, with narrow, curved golden scales periskelta, Giles. αα. Legs with basal and apical banding. Fore legs with no bands; mid with apical and basal bands on first and second tarsals, hind with basal bands. Thorax white in front, with a brown eye-like spot on each side thomsoni, Theobald. AA. Proboscis unbanded. β. Legs basally banded. γ. Abdomen basally banded. Thorax with one median silvery-white line scutellaris, Walker. Thorax as above, but pleuræ with white lines pseudoscutellaris, Theobald. Thorax similar, but two white spots near where line ends gelebinensis, Theobald. Thorax with two median yellow lines and lateral curved silvery lines fasciata, Fabr. Thorax with two short median lines and a white patch on each side nigeria, Theobald. Thorax with large lateral white spots in front, smaller ones by wings, two narrow median lines and two posterior sub-median white lines lilii, Theobald. Thorax with a white *W*-shaped area in front, a prolongation curved on each side enclosing a brown eye-like spot W-alba, Theobald. Thorax with white frontal median spot, two large lateral spots, a small one in front of the wings, a narrow median white line and narrow sub-median ones on posterior half. _Last two hind tarsi white_ wellmannii, Theobald. Thorax brown, with broad white line in front extending laterally towards wings, where they swell into a large patch, a white line on each side just past wing roots. _Last two hind tarsi white_ albipes, Theobald. Thorax with silvery white spot on each side in front, small one over roots of wings and white over their base. _Last two hind tarsi white_ pseudonigeria, Theobald. Thorax with two lateral white spots, front ones the largest, a small median one near head, two yellow median lines, a short silvery one on each side before the scutellum simpsoni, Theobald. Thorax with silvery-white scaled area in front and another on each side in front of wings argenteomaculata, Theobald. Thorax with median yellowish-white line, a silvery patch on each side in front of wings extending as a fine yellow line to the scutellum, and another silvery spot before base of each wing poweri, Theobald. Thorax with small grey-scaled area in front of wing roots and three short creamy lines behind minutissima, Theobald. Thorax (?) denuded; abdomen black; fifth segment with yellow basal band; sixth unbanded; seventh, two median lateral white spots; eighth, two basal lateral white spots; second hind tarsal nearly all white dubia, Theobald. γγ. Abdomen unbanded. First hind tarsal all white, second basally white, last two dark. Thorax chestnut brown, with a broad patch of white scales on each side in front and a median pale line terreus, Walker. ββ. Legs with white lines as well as basal bands. Thorax brown, with white lines; abdomen with basal bands grantii, Theobald. βββ. Fore and mid legs with apical bands, hind basal. Fourth tarsal of hind legs nearly all white mediopunctata, Theobald. Mid metatarsi with basal pale banding, base and apex of hind, also base of first tarsal pale assamensis, Theobald. ββββ. Legs unbanded. δ. Abdomen basally banded. Thorax with front half white, rest bronzy-brown pseudonivea, Ludlow. Thorax deep brown, with scattered golden scales, showing two dark eye- like spots; head white, dark on each side and behind albocephala, Theobald. Thorax brown with golden stripes; abdomen with narrow basal bands on fifth and sixth segments only auriostriata, Banks. δδ. Abdominal banding indistinct. Thorax with broad silvery white patch on each side in front albolateralis, Theobald. δδδ. Abdomen unbanded. Thorax with six silvery spots argenteopunctata, Theobald. δδδδ. Abdomen with apical white lateral spots. Thorax unadorned, except for pale scaled lines laterally punctolateralis, Theobald. δδδδδ. Abdomen with basal white lateral spots. Thorax with two pale median parallel lines and two silvery lateral spots ininuta, Theobald. Thorax unadorned. A white spot middle of head tripunctata, Theobald. No white spot amesii, Ludlow. AAA. Proboscis yellow basally, dark apically. Abdomen with apical pale bands crassipes, Van der Wulp. AAAA. Proboscis with median interrupted white line on basal half. Head black, anterior margin grey albomarginata, Newstead.

*Stegomyia fasciata*, Fabricius (Yellow Fever Mosquito).

This insect, which is the proven carrier of yellow fever, is commonly called the tiger, brindled, spotted day or striped mosquito. It is also referred to by some writers as S. calopus, Meigen. It is subject to considerable variation in colour, but the thoracic markings are generally very constant. The general colour is almost black to deep brown, the head with a median white area, white at the sides and in front around the eyes; the thorax has two median parallel yellow lines, a broad curved silvery one on each side and white spots at the sides; the scales on the intervening spaces of the thorax are brown. The dark abdomen has basal white bands and basal white lateral spots. The dark legs have basal white bands, the last segment of the hind legs being all white except in a variety from South America and the West Indies (luciensis), which has the tip of the last hind tarsal dark. The abdomen may also vary in colour, some having pale scales over most of the surface (queenslandensis).

The food of the adult female consists mainly of man’s blood, but she will also feed on dogs and other animals. The male has been said to bite, but such is very unusual. This mosquito bites mainly in the daytime up till about 5 p.m.

The adults breed the first day after emergence. They may live a considerable time, Bancroft having kept females for two months in confinement. The ova are laid separately, often in chains; they are black, oval, with a reticulated membrane outside, some of the reticulated cells containing air. They may hatch in from six to twenty hours, the larval stage nine days, the pupal stage three; thus the whole cycle may be completed in from twelve to thirteen days. The ova when dry can remain undeveloped for a considerable time. The larvæ are greyish-white, with short, thick siphon, and feed at the bottom of the water, only coming to the surface now and again to breathe. This is almost entirely a domesticated gnat, seldom being found far from man’s habitations. Its larvæ occur in such small collections of water as old sardine tins, jam-pots, calabashes, puddles, barrels, wells--in fact, wherever water is held up, even to the gutters of houses. Not only are they found breeding on land, but also on board ship, although they prefer artificial collections of water. They may also breed in larger natural collections.

This insect is easily transported by steam and sailing ships and by train, and this doubtless explains its very wide distribution. The adults may live for fifty days, and it is on this account and their frequent occurrence on ships that danger lies in regard to the Panama Canal. An infected insect may leave that endemic centre of yellow fever and live until the vessel arrived at the Philippine Islands and fly ashore, and so introduce the disease for the native fasciata possibly to spread.

Roughly the distribution of this pest is as follows: Africa from South to North, but especially along the coast and up the Nile. In Asia, in India, Ceylon, Burma, Siam, along the ports of the Malay Peninsula, in French Cochin China, Philippine Islands, the Andaman and Nicobar Islands, Japan, Malay Archipelago, and East Indies, Turkey in Asia, Arabia and Palestine.

In Australia it occurs in Queensland, New South Wales, Victoria and South Australia.

In Europe in Italy, Spain, Portugal, Greece, in the Mediterranean Islands.

In South America, Central America, Mexico, North America, and the West Indies it is very abundant, and it also is found in the Bahama Islands, Fiji, Sandwich Islands, Samoa, the Azores, Teneriffe and Santa Cruz, Pitcairn Islands and Bermuda.

For a full account of its distribution the reader is referred to the following: “The Distribution of the Yellow Fever Mosquito (Stegomyia fasciata, Fabricius) and General Notes on its Bionomics;” “Mém. 1^{er} Congrès international d’Entomologie, 1911, ii, pp. 145–170, F. V. Theobald.” In addition to being the yellow fever carrier, it is supposed by Wenyon to be the intermediate host of the parasite of Bagdad sore.

*Stegomyia scutellaris*, Walker.

A vicious biter, found in India, China, Malay, East Indies, and Ceylon. The thorax has one median silvery stripe, and so can easily be told from S. fasciata.

A very similar species occurs in Fiji, but can be told by the pleuræ having white lines, not spots (S. pseudoscutellaris, Theobald). It is the intermediate host of filaria in Fiji (Bahr).

A number of nearly allied genera occur here (vide synoptic table).

Genus. *Theobaldia*, Neveu-Lemaire.

*Theobaldinella*, Blanchard.

Includes several large Culicines, of which T. annulata, Meigen, is the type. The wings are usually spotted (annulata, incidens, etc.), but may be nearly plain (spathipalpis). The males have the palpi swollen apically, and the females have long five-jointed palps.

Several of these are vicious biters.

*Theobaldia annulata*, Meigen.

This large gnat (6 mm. long) can be told by its wings having five large spots of dark scales and by its legs having broad basal white bands to the tarsi. The larvæ occur in rain barrels and small pools. It is essentially a domestic form, occurring in houses and privies. Its distribution is Europe generally and North America. The bite is very severe, and in some districts gives rise to painful œdema.[392]

[392] Theobald, “Second Report on Economic Zoology,” 1903, p. 9.

Theobaldia spathipalpis, Rondani, occurs in Italy, Mediterranean Islands, Palestine, the Himalayas, Khartoum, and in South Africa. It is about the same size as T. annulata, but is yellowish-brown in colour, with striped thorax and mottled and banded legs. It occurs in privies and bites very severely.

Genus. *Culex*, Linnæus.

“Syst. Nat. Ed.,” 1758, x, Linnæus; “Mono. Culicid.,” 1901, i, p. 326; 1910, v, p. 322, Theobald.

This large genus still contains many forms which should be excluded. The species normally have narrow curved median head-scales, and similar ones on the scutellum; the female palpi are shorter than in the former genus and the male palpi are pointed; the lateral vein-scales are narrow and linear.

The type is Culex pipiens, Linn., the common gnat of Europe. The thorax is covered with narrow curved golden-brown scales, the abdomen has basal pale bands to the segments and the legs and proboscis are unbanded. The stem of the first submarginal cell is always less than one-fifth the length of the cell. It lays its eggs in rafts in water-butts, etc., and even in the foulest water. They are first deposited in England in June and July, and again soon after hatching in August. In some districts this gnat bites man viciously, in others not at all.

The common tropical gnat (Culex fatigans, Wied). This resembles the European Culex pipiens, but can always be told by the stem of the first submarginal cell always being much longer than it is in C. pipiens. This is one of the species that has been proved to transmit filariæ to man, etc. Varieties of it occur in almost every country between 40° N. and S., having a very similar range to S. fasciata. In all countries it appears to be connected with the transmission of Filaria bancrofti, and it is also said to carry the micrococcus of dengue fever.

Genus. *Melanoconion*, Theobald.

“Mono. Culicid.,” 1903, iii, p. 238; 1907, iv, p. 507; 1910, v, p. 455.

This genus is composed of eight species, most of which are small black gnats which bite viciously and which occur in swamps and jungles. They can at once be told from Culex by the veins of the wings having dense broadened scales on their apical areas and along the upper costal border. The femora and apices of the tibiæ are swollen.

The black mosquito, Melanoconion atratus, Theob. This small gnat is a very troublesome pest in swamps in the West Indies. The female bites both by day and by night, and the bite causes severe irritation. The larvæ live in permanent ponds. It is almost black in colour, but sometimes presents a dull coppery sheen; each segment has small lateral basal white spots. Length 2·5 to 3 mm.

It occurs in Para and British Guiana as well as in the West Indies.

Ordinary mosquito netting is no use for keeping off this pest.

Genus. *Grabhamia*, Theobald.

“Mono. Culicid.,” 1903, iii, p. 243; 1907, iv, p. 284; and 1910, v, p. 277.

Allied to Culex, but separated by the wings having short fork-cells, mottled scales, the median ones thick and also some of the lateral ones short and broad; the last two joints of the male palps are very slightly swollen. The eggs are laid singly, not in rafts, and the larvæ have short, thick siphons. Ten species occur and are found in Europe, North America, West Indies and Natal. G. dorsalis, Meigen, bites severely in Europe. G. sollicitans, Walker, is a great scourge along the New Jersey Coast and at Virginia summer resorts and in Florida. It breeds in brackish water and is the most common mosquito of the Atlantic seaboard.

Genus. *Pseudotæniorhynchus*, Theobald; *Tæniorhynchus*, Theobald, non-Arribalzaga.

Differs from the former in having the whole wing veins clothed with dense, broadish elongated scales. They occur in South America (T. fasciolatus, Arri.), in Africa (T. tenax, Theob.), in Europe (T. richardii, Ficalbi). The latter bites very severely.

Genus. *Tæniorhynchus*, Arribalzaga; *Mansonia*, Blanchard; *Panoplites*, Theobald.

Compt. rend. heb. Soc. Biol., 1901, iii, 37, p. 1046; “Mono. Culicid.,” 1901, ii, p. 173; and 1910, v, p. 446, Theobald.

A very marked genus, easily told by the broad asymmetrical wing scales. It occurs in Africa (T. africana and T. major, Theob.); in Asia (T. uniformis, Theob.; T. annulipes, Walker, etc.) and in Australia (T. australiensis); in the Americas and West Indies (T. titillans, Walker). The eggs (fig. 395, d) are peculiar in form and are laid separately; the larva has not been described; the pupa has long curved siphons. They mostly occur along rivers, in swamps and forests, and bite very severely. They also enter houses (T. titillans). T. uniformis is most troublesome during the rains. The saliva is strongly acid. Both these species carry the larvæ of Filaria bancrofti.

Genus. *Chrysoconops*, Goeldi.

“Os Mosq. no Para,” 1905, p. 114, Goeldi; “Mono. Culicid.,” 1910, v, p. 433, Theobald.

Bright yellow or yellow and purple mosquitoes, with rather dense wing scales. Numerous species occur in Africa (aurites, annettii, fuscopennatus, etc.), others in India, Australia and South America.

Low found filariæ in the thoracic muscles of fuscopennatus in Uganda.

Several of the Ædeomyina bite, especially the small Uranotænias. They are all sylvan species, seldom entering houses. They need not, therefore, be referred to here.

For full details of the Culicid genera and species the reader is referred to my monograph[393] and other works mentioned below.

[393] “A Monograph of the Culicidæ of the World,” 5 vols. and atlas, 1901 to 1910, British Museum (Nat. Hist.); and the following: Howard, Dyar and Knab, “The Mosquitoes of North and Central America and the West Indies,” 1912; James and Liston, “The Anophelinæ of India,” Leicester, 1908; “The Culicidæ of Malay,” Inst. Med. Res., Fed. Malay States, iii; Ann.Trop. Med. and Par., papers by Newstead and Carter; Mem. Inst. Oswaldo Cruz, papers by Lutz, Neva, Chagas; and the Bulletin of Entomological Research, etc.

Other Nematocera.

Other nematocerous flies are midges, daddy-long-legs and sand-flies. The ones which cause annoyance to man besides Culicidæ are the following:--

Sand-flies (Simulidæ), certain midges (Chironomidæ), and a few owl midges (Psychodidæ).

The Nematocera have long thread-like jointed antennæ and their pupæ are, as a rule, naked; the larvæ have a distinct head and can thus be told from the next section (Brachycera).

Family. *Simulidæ.*

This family consists of a single genus, Simulium, Latreille, which Roubaud has recently divided into two sub-genera called Pro-Simulium and Eu-Simulium. These insects, which are frequently spoken of as sand-flies, are found in all parts of the world; they are all small insects varying from 1·5 to 3 mm. The females are very bloodthirsty, but the males appear to be incapable of sucking blood.

The head sunk under the humped thorax; antennæ short, straight; palpi short and broad, of four segments, bent; wings broad and in some iridescent, legs stout. The male has holoptic eyes, whilst in the female they are small and widely separate. The sucking proboscis is short. The thorax and abdomen are clothed with short hairs which may form spots and markings; these are golden, silvery, grey, or brownish. In the sub-genus Pro-Simulium the second segment of the hind tarsi in both sexes is elongate, linear, and without a basal notch; in Eu-Simulium it is short, curved, and dorsally notched at the base.

Simulidæ often occur in swarms, and attack not only man but cattle, horses, and poultry. In some districts they are more annoying than mosquitoes.

Their life-cycle has been most completely worked out by King, in Africa.

The larvæ and pupæ occur in swiftly flowing water, by waterfalls, in rapids, etc. The ova are laid in gelatinous masses on plants or rocks close to or overhanging the water. The larva is cylindrical, enlarged posteriorly, where it is provided with a sucker, by means of which it attaches itself to a rock, water weeds, debris, etc.; anteriorly it has a proleg close behind the head on the lower surface. The head is dark and chitinous. The respiration takes place by means of branched tracheal gills which protrude from the dorsal surface of the last body segment; they are retractile. The colour varies from deep green to yellow or almost black. Their food consists of algæ and other organisms in the water brought to their mouth by two fan-like organs placed on the head. The larvæ can crawl from place to place by means of the thoracic proleg; they occur in masses, usually in a more or less erect attitude. A network of threads is spun on their support, by means of which King tells us “they are enabled to maintain their position against the strongest current; frequently they will leave their support and let themselves out into the stream anchored by threads of silk and enabled by them to return.”

When full fed the larva spins a pocket-shaped cocoon on the support, within which it pupates. The pupa is motionless and has a pair of branched spiracles projecting from behind the head. When the adult emerges, a bubble of air collects around it, and in this it floats to the surface and at once takes wing. The European species take a month to complete larval life, a week being spent in the pupal stage. The flies are most restless, and even when stationary continually move their legs about like feelers. Sometimes the swarms consist entirely of females, sometimes early in the season mostly of males.

The females pierce the skin of humans on tender spots, such as ears, the forehead, around the eyes and nose, and crawl into the cavities. They are quite harmless at night, mainly attacking about sunrise and sunset. Some crawl up the arms and legs and down the neck, and leave behind little red weals which itch intensely (S. damnosum, Theob.), and blood may flow freely from the wounds.

The following are some of the worst species:--

Simulium columbaschensis, the “Kolumbatz fly,” which abounds in the damp marshy lands along the Danube, and is a great plague to man and beasts in Hungary, and is also abundant in Austria and Moravia, and is most numerous after inundations from the Danube. They sometimes appear in such swarms that it is impossible to breathe without getting them into one’s mouth. There are instances of children being killed by these flies when left on the ground by their mothers when working in the fields.

S. damnosum, Theob. This occurs throughout Equatorial Africa and is known as the “jinja fly” in Uganda, the “fouron” in the French Congo, the “kilteb” in the Sudan. It is a most vicious biter, and in some parts occurs in “belts”; Dr. Christy found one such extending from the shores of the Victoria Nyanza northwards along the right bank of the Nile for twelve or fifteen miles or more, and perhaps three or four miles wide. In this area the flies swarm in millions at certain seasons, so much so that the natives have to leave their plantations. The bite causes a weal, marked by a drop of blood.

S. griseicollis, Becker. The so-called “nimitti” occurs in Upper Egypt and the Anglo-Egyptian Sudan. It lives near the river and is not found more than half a mile from it. Human beings are bitten on the face and hands, animals in the region of the pudenda.

S. latipes, Meigen. This is a European species, also found in Natal.

S. wellmanni, Roubaud. The “ohomono” of Angola, where it bites viciously and is dreaded by the naked porters.

S. buissoni, Roubaud. Occurs in abundance in the Marquesas Islands. It has been suggested that this species may help to propagate leprosy.[394]

[394] Bull. du Mus. d’Hist. nat., 1906, xii, p. 522.

A large number of these insects have been described by Lutz in Brazil.[395]

[395] Mem. Inst. Oswaldo Cruz, 1910, ii, fasc. 2, pp. 211–267.

A Simulium sp. (?) is very harmful to poultry in Cape Colony.[396]

[396] C. Fuller, “A New Poultry Pest,” 1899, Leaflet No. 1, Dept. Agric.

In America, Simulidæ are most annoying. One, S. meridionale, Riley, also known as the turkey gnat in the Mississippi Valley, has been supposed to be the carrier of chicken cholera; anyhow, it has caused the death of thousands of chickens and turkeys in Virginia annually.[397]

[397] Insect Life, 1888, i, p. 14.

In Mexico Townsend found a Simulium which was named S. occidentalis, which caused great annoyance to man, many people being so susceptible to them as to preserve through the gnat season a chronic inflammation of the exposed parts of face and neck, resulting from the repeated bites giving rise to sores.[398]

[398] Ibid., 1893, v, p. 61.

Men and horses have been partially incapacitated by the bites of sand-flies or Simulium in a Hampshire wood (Cantlie, Brit. Med. Journ., April 28, 1900, v, No. 2,052, p. 1023).

Family. *Chironomidæ* (Midges).

The Chironomidæ or midges are not only frequently mistaken for mosquitoes, but some are very annoying to man by biting him as mosquitoes do. They are easily distinguished from true mosquitoes (Culicidæ) by the following characters: (1) head small, often retracted under the cowl-like thorax; (2) no scales to the wings or body; and (3) the different arrangement of veins on the wings (fig. 402).

Two genera are important as annoying man, namely, Culicoides, Latreille, and Johannseniella, Williston. The larvæ of Chironomidæ are either aquatic, both fresh water and marine, and help to make the former foul,[399] according to Slater, or may, as in Ceratopogoninæ, live beneath the bark of trees, etc. The pupæ are very varied and also the life-histories of the different genera.[400] The blood-sucking habit is confined to the sub-family Ceratopogoninæ.

[399] Entomologist, 1879, p. 89.

[400] Theobald, “An Account of British Flies,” i, p. 172.

Sub-family. *Ceratopogoninæ.*

This sub-family of midges consists of very small species varying from 1 to 2 mm. in length; the wings have darkened areas, and the second longitudinal vein is wanting, and the first and third veins are stouter than the others and placed close to the anterior margin, the fourth and fifth are forked; the antennæ in both male and female are composed of fourteen segments, six or eight in the males bearing long hairs.

The chief blood-sucking species belong to the genera Culicoides, Latreille, and Johannseniella, Williston. The latter genus differs from the former in the absence of an empodium or median appendage on the last segment of the tarsi. The genus Ceratopogon, as restricted by Kieffer, is not supposed to take vertebrate blood, but Austen has recently noticed that the type specimen of C. castaneus, Walker, and a new species described by him, apparently have their bodies distended with blood. The wings in the Ceratopogoninæ are carried flat when at rest.

In spite of their small size the females are the most bloodthirsty and annoying of all insects. The Culicoides, which are often called “sand-flies,” bite during the day and rarely at night. Usually they are most troublesome between 3 and 6 p.m. They frequently attack in swarms, especially in the open, and owing to their minute size can get through fine mosquito netting. Some of them produce a distinct “buzz” when on the wing. These insects are found in all parts of the world. No species has been definitely connected with any disease, but Culicoides has been suspected of carrying the germs of Delhi boil. The larvæ of Culicoides are elongate in form and have smooth bodies composed of thirteen segments including the head, which is horny; there is no proleg on the first segment as seen in Chironomus, and on the anal segment are retractile gills. They are very active and live in the sap of various trees which saturates diseased bark.

The pupæ are smooth, but the abdominal segments bear a transverse row of small spines. Austen describes a number of Culicoides and one Johannseniella and three Ceratopogons from Africa,[401] and Lutz[402] a number of this sub-family from Brazil, including a new genus, Centrorhyncus. Another genus, Tersesthes, Townsend (Centrotypus, Grassi; Mycterotypus, Noe), also occurs in Brazil.

[401] Bull. Ent. Res., 1912, iii, pp. 99–108.

[402] Mem. Inst. Oswaldo Cruz, 1913, v, fasc. 1, pp. 45–72, pls. 6–8; and 1914, vi, fasc. 2, pp. 81–99.

Culicoides ornatus, Taylor, is described from Townsville, Australia, found in mangrove swamps. It is a very vicious biter and causes considerable irritation, settling on hands and wrists (Taylor, Rep. Ent. Aust. Inst. Trop. Med. (1912), 1913, p. 24).

Family. *Psychodidæ* (Owl Midges).

This family of diptera is of considerable importance, not only on account of the blood-sucking habits of some species, but especially on account of one at least having been proved to be the carrying agent of “papataci” fever, a three-day fever very prevalent in Malta and several parts of Southern Europe in the autumn.

It is also possible that these small flies are connected with the formation of “Delhi boil,” caused by a protozoan parasite.

Psychodidæ are all very small flies, many of which have a moth-like appearance, and owing to their fluffy nature are spoken of in Britain as “owl flies,” sometimes also as “window flies.” Their bodies and wings are covered with hairs, densely in some (sub-family Psychodinæ), and in a few with patches of flat squamæ. In the non-blood-sucking Psychodinæ the wings are carried in a peculiar manner downwards over the body, to a slight extent resembling the Hepialidæ, or swift moths. The wings may be ovoid or lanceolate, and have a marked venation as seen in the figure. The proboscis is short and non-suctorial in the majority of genera, but in the sub-family Phlebotominæ it is elongated and hard. The antennæ are long and of sixteen segments, and bear whorls of fine hair.

There are two sub-families, Psychodinæ and Phlebotominæ; in the former the mouth is not suctorial; the female has a horny ovipositor and the second longitudinal vein is branched at the root of the wing; in the second sub-family the proboscis may be formed for sucking, the female has no horny ovipositor, and the second long vein has its first fork near the middle of the wing.

The sub-family Phlebotominæ contains the genus Phlebotomus, which occurs in South Europe, South Asia, Africa, North and South tropical America. They are all small grey, brown, or dull yellow-coloured flies, and carry their wings when at rest upwards like a butterfly. The proboscis is moderately long and the legs long and thin.

The females are most vicious blood-suckers, but in some species anyhow the males also bite (P. duboscii). They are mainly nocturnal feeders and hide away during the day in any dark corners or crevices.

The life-cycle has been worked out by Newstead[403] and Grassi[404] in Europe, and by Howlett[405] in India.

[403] Bull. Ent. Res., 1911, ii, pt. 2, pp. 47–78.

[404] “Ricerche sui Flebotomi,” Mem. della Soc. ital. della Scienze, 1907, ser. 3, xiv, pp. 353–394.

[405] “Indian Sand-flies,” Ind. Med. Cong., 1909, sec. III, pp. 239–242.

The larvæ have been found in crevices in rocks and caves, in dirty cellars, and dark damp places containing rubbish, and are also said to live in crevices in the walls of privies and cesspits.

The minute larva is very marked; as figured by Newstead it has two long chætæ projecting upwards, in some stages branched, in others simple, and on the segments a few blunt spine-like processes. The pupæ are found in similar situations. The ova are very minute, elongate, translucent white, and covered with a thin coating of viscous matter when first laid; soon after they become dark brown, shiny, with long black wavy lines. Newstead found the incubation period in Malta to last for about nine days in P. papatacii. Five species are known in Europe, five in Africa,[406] two in North America, and eight are described by Annandale[407] in the Oriental region. Lutz and Neiva have described three species from Brazil[408] (P. longipalpis, intermedius and squamiventris).

[406] Newstead: Bull. Ent. Res., 1912, iii, pp. 361–367.

[407] Rec. Ind. Mus., v, pt. 3, Nos. 13 and 14.

[408] Mem. Inst. Oswaldo Cruz, 1912, iv, fasc. I, pp. 84–95.

*Brachycera* (Flies).

The antennæ as a rule have three segments, and are usually shorter than the head. The first segment of the antennæ is frequently very small, and the third one is generally the largest, and sometimes possesses a terminal annulated bristle. The palpi have from one to three segments; the mandibles are covered by the labium. The three thoracic rings are coalesced; wings are almost always present, the posterior ones being rudimentary and covered with a little scale. From the ova legless maggots are hatched, which as a rule have not a distinct head, but occasionally possess two claw-like hooklets. These maggots live in decomposing organic matter; they rarely live in water and some of them are parasitic. They either become barrel-shaped pupæ within the last larval integument or, after casting it, are transformed into naked pupæ. The larvæ of numerous Brachycera have been observed in man, some in ulcers or on mucous membranes, others in the skin or in the intestine, etc. In many cases the report only mentions the presence of the larvæ of flies; in other cases the species has been determined; whilst in still other cases the corresponding adult creature is unknown. We must therefore confine ourselves to describing the most common varieties.

Family. *Phoridæ.*

These flies belong to the same division of Diptera, the Aschiza, as the family Syrphidæ or “hover flies.” They are all small insects with marked antennæ and wings; the former have the third segment globular and enlarged, and thus hiding the first two; the wings are short and broad, the venation shows two short, thick, long veins with four thin ones running out from them. The larvæ normally live in decaying animal and vegetable matter, but one species, Aphiochæta ferruginea, Brun., has been found as an intestinal parasite of man.

*Aphiochæta ferruginea*, Brun.

This small fly belonging to this family is of an orange-ochreous colour, the upper part of the thorax tawny, and with dark bands on the abdomen, legs pale yellow, the hind femora tipped with dark brown. It measures only 2 to 3 mm. in length. This insect is shown by Austen to be widely distributed in the tropics, being found in India, Burma, West Africa, and Central America. The larvæ breed in decaying animal matter, such as putrid meat, decomposing shell-fish, etc.

Heusner bred out sixty-three flies from larvæ taken from an Indian’s foot.

Baker (Proc. Burma Branch Brit. Med. Assoc., 1891, p. 11–16) found that the maggots of this fly were passed per anum by a European at intervals during a period of ten months. Baker found that the larvæ fed on human fæces; from the egg stage to the deposition of eggs from the resultant brood of flies occupied twenty-two days. He concludes that they are capable of propagating, and do so while living within the human intestines. He also records the larvæ in two girls.

The larva does not seem to have been described, but Austen describes the pupa (Trans. Soc. Trop. Med. and Hyg., iii, No. 5, p. 229).

*Phora rufipes*, Meig.

The larvæ of the “hump-backed fly” live in rotting potatoes, mushrooms, radishes, etc., and when accidentally introduced into the intestine of man can, like other larvæ, live there twenty-four hours and even more, and may set up serious gastric disturbances.

P. rufipes is the same as P. pallipes, Latr.

Family. *Sepsidæ.*

Small blackish flies, elongate, with abdomen narrowed at the base, thickened and curved downwards towards the extremity. Larvæ often found in decaying vegetables, ham, cheese, etc. The larvae have the power of skipping; conical in form, pointed in front, truncated behind, about 5 mm. long, shiny and smooth, the anal segment with fleshy protuberances. The genus Piophila has a short proboscis and the cross-veins of the wings approximate.

*Piophila casei*, L.

Cheese flies. The larvæ live in ripe cheese, with which they are sometimes introduced into human beings (Meschede).

The larvæ of the cheese flies (Piophila casei) may pass through the alimentary canal of human beings alive, and have been occasionally referred to in cases of internal myiasis. It also breeds in dead bodies in adipose tissue. Howard records it on human excrement. It is thus possible that some of the recorded cases of this pest being passed alive may be due to eggs deposited on human fæces.

Family. *Syrphidæ* (Hover and Drone Flies).

Amongst the large family of Syrphidæ is found a section known as the Eristalinæ or drone flies, whose curious long-tailed larvæ are popularly called “rat-tail larvæ,” on account of the end of the body being drawn out into a long telescopic tail of two segments, at the end of which are placed the breathing pores. These larvæ live in water, no matter how foul, and in liquid manure. They have occasionally been obtained in foul drinking water by human beings and from eating watercress improperly washed or from badly kept beds. Austen (Trans. Soc. Trop. Med. and Hyg., iii, No. 6, p. 221) records that in the autumn of 1907 a number of the larvæ of the common drone fly (Eristalis tenax) were passed per rectum by a woman in Hampshire who had recently arrived from France. The patient had eaten a considerable quantity of watercress before leaving France. I have twice found small Eristalis larvæ clinging by their long tails on watercress served at table.

Family. *Drosophilidæ.*

Small, rather plump flies, with short, broad abdomen, with bristles on the head and legs. Often abundant in decomposing fruit, and may occur in dense masses.

*Drosophila melanogaster*, Br.

The larvæ of this fly occur in over-ripe fruit and in fungi, often also in human habitations, and live in substances undergoing acid fermentation (vinegar, decaying fungi, rotting fruit, in damaged spots in diseased trees), much more rarely in animal substances, and they occasionally gain access to the human intestine (for example, by the medium of sour milk). When introduced in any quantity, they cause vomiting or attacks resembling colic; when taken in the pupal stage no unpleasant results are produced.

Family. *Muscidæ.*

*Teichomyza fusca*, Macq.

Syn.: Scatella urinaria, Rob. Desv.; Ephydra longipennis, Meigen.

The larvæ live in the urine in privies. Several authors state they have found them in fresh fæces or in vomited matter. Pruvot states that they continue for three days in the stomach of rats into which they have been intentionally introduced. (Pruvot, G., “Contrib. à l’étude des larves de dipt, trouv. dans le corps humain,” Thèse de Par., 1882; Chatin, J., in Comp. rend. Soc. de Biol., Paris, 1888 (8), v, p. 396; Roger, H., ibid., 1851 (1), iii, pp. 88, etc.)

*Homalomyia canicularis*, L., etc.

Homalomyia manicata, Meig., live as larvæ in decomposing vegetable matter or in cultivated vegetables (cabbage); they are easily recognizable by their plumed bristles, which are situated laterally on the body segments. They obtain access fairly often to the human intestine and give rise to very uncomfortable symptoms. Cases have been recorded from Germany, Austria, France, England, North America (Wacker, in Artzl. Intelligenzbl., 1883, xxx, p. 109; Florentin, in Compt. rend. Soc. de Biol., Paris, 1904, lvi, p. 525; and other authors).

The larvæ of an allied genus (Anthomyia), which, however, does not possess plumed bristles, has been found in the external auditory meatus of a man (A. pluvialis, according to Danthon).

[H. canicularis is common to Europe and North America, and is an abundant house-fly. It is the small house-fly so often seen on windows. Besides living on vegetable matter, they have also been found in the nests of the humble bee. Larvæ of this species (fig. 405) were sent to the British Museum, taken from the fæces of a woman suffering from cancer.[409] They were found at Shrewsbury. Hagen[410] reports the larvæ of this fly as occurring alive in the urethra of a patient.--F. V. T.]

[409] Theobald, “First Report Economic Zoology,” Brit. Mus. (Nat. Hist.), p. 55.

[410] Hagen, Proc. Bost. Soc., N.H., xx, p. 107.

*Homalomyia scalaris*, Fabr.

[This is not a synonym of the above, but a distinct species.

[H. manicata, Meigen, is also distinct.--F. V. T.]

*Anthomyia desjardensii*, Macq.

This fly, allied to Homalomyia, is the cause of both intestinal and cutaneous myiasis at Bihé, Angola (Wellman, Journ. Trop. Med. and Hyg., June, 1907, x, p. 186).

*Hydrotæa meteorica*, L.

The larvæ live in decaying vegetable substances, also in dung, and have been evacuated in some cases by man (Zetterstedt, Joseph).

*Cyrtoneura stabulans.*

Larvæ in fungi, but occasionally also on larvæ of butterflies and Hymenoptera; occasionally introduced into the human intestine (Joseph).

*Musca domestica*, L.,

and M. (Calliphora) vomitoria, L., and allied species; larvæ of these have been repeatedly found in the intestine and nose of man (Mankiewicz, etc.).[411]

[411] “Larvæ of a Musca, probably M. corvina, were passed in numbers per rectum by a child in Liverpool with Homalomyia larvæ,”--“Second Report Economic Zoology,” Theobald, 1903, p. 16.

*Musca domestica*, Linn. (Common House-fly).

It is not only on account of a few larvæ of the common house-fly (Musca domestica) being found in the intestines of man that it is of importance medically. It is far more important on account of the part it plays in the spread of diseases of the intestines, such as typhoid fever and cholera, infantile diarrhœa and dysentery.

Howard and Clark (Journ. Exp. Med., 1912, xvi, No. 6, pp. 850–859) have shown that the house-fly is capable of carrying the virus of poliomyelitis for several days on the surface of the body and for several hours in the gastro-intestinal tract. The house-fly may also distribute the ova of Tænia solium and the white worms (Oxyuris and Ascaris). It has also been proved that they may carry the germs of tuberculosis, and it is said that they play an important part in the spread of infectious ophthalmia in Egypt.

This insect is found in all parts of the world. In warm countries it breeds all the year round, and it may do so even in temperate climates in warm places, such as stove houses. Most, however, die off in the autumn; but some survive the winter as adults, in such places as kitchens, restaurants, and warm houses. I have never failed to find a few Musca domestica in houses during the winter. The majority, however, hibernate as puparia.

The females deposit from 120 to 150 eggs in a batch in stable manure, rotting vegetation, house refuse, spent hops, old soiled bedding, etc. A single female may lay as many as six batches of ova during her life. The eggs are shiny white, and hatch in from eight to twenty-four hours in warm weather to three or four days in cool weather. The white footless maggots are cylindrical, tapering to a point at the head end, truncated posteriorly. The head consists of two dark mandibular hooks and two short antennæ. On the tail end are two plates, the stigmata, in which the main tracheal trunks open; in the second segment are a small pair of projecting stigmata. The larval stage lasts from seven to five days in hot weather; but in cold weather in temperate climes it may last six or eight weeks.

The larva on reaching maturity becomes a barrel-shaped puparium of a dark brown to black colour, and in this case changes to the pupa. This stage lasts from three days in the tropics to four or five weeks in cold weather, the life cycle thus varying from ten days in the tropics to fourteen in warm weather in Europe up to three or four months under unfavourable conditions.

All breeding grounds should be burnt or otherwise done away with, such as stable manure, house and kitchen refuse, human excrement and soiled substances, also decaying vegetation as soon as possible, certainly by every sixth day. Stable manure should be kept in closed receptacles and should be removed by every sixth day to at least one mile from habitations and sprinkled with chloride of lime. All kitchen and household refuse should be burnt at once or buried in pits and covered with soil. Latrines should be as far as possible from hospitals, mess rooms and tents. Food--especially milk, sugar and fruit--should be kept screened with muslin when house-flies are about. Mess rooms and tents and hospitals should have doors and windows screened with fine wire gauze during the fly season. All possible steps should be taken to prevent them contaminating man’s food and from breeding in human excrement and from entering hospitals. When present in dwelling-houses in numbers they may be killed by fumigation with pyrethrum or sulphur.

Genus. *Chrysomyia*, Rob. Desv.

*Chrysomyia* (*Compsomyia*) *macellaria*, Fabr.; *Lucilia macellaria*, Fabr.

Syn.: Lucilia hominivorax, Coq.; Calliphora infesta, Phil.; Calliphora anthropophaga, Conil.

A species distributed from the Argentine to the south of the United States which deposits its ova on ulcers, in the aural meatus or in the nasal cavities of persons who sleep in the open air. The larvæ are yellowish white, 16 mm. long, are armed with two strong mouth hooks, and provided with spinous rings (screw-worm); they lie hid in the nasal and frontal sinuses, in the pharynx, larynx, etc.; they perforate the mucous membranes, even cartilage, migrate into the eyes, the cranial cavity, middle ear, and cause severe disturbances; after the mature stage, in which the larvæ leave the host to enter the pupal state, these symptoms often spontaneously abate after a lapse of eight days, leaving behind greater or less cicatrices, and consequently also defects in function of the organs attacked. Very often, however, sepsis sets in, usually with a fatal termination.

(Coquerel in: Arch. gén. de méd., 1858 (5), p. 513; 1859, xiii, p. 685; Ann. Soc. ent. France, 1858 (3), vi, p. 171; 1859, vii, p. 234. Weber in: Rec. de mém. de méd. milit., 1867 (3), xviii, p. 159. Francius, A., in: Arch. f. path. Anat., 1868, xliii, p. 98. Conil in: Bol. Acad. nac. cienc. Cordoba, 1881, iii, p. 296. Humbert, Fr., in: Proc. U.S. Nat. Mus., 1883, vi, p. 103; Amer. Nat., 1884, xviii, p. 540. Lindsay in: Journ. Trop. Med., 1902; v, p. 220, and other authors.)

[This species is known as the screw-worm fly. It attacks animals as well as man, especially laying its eggs on wounds formed by barbed wire. It may also be found on dead flesh. Dr. St. George Gray sent me specimens from St. Lucia, from the nose and mouth of a patient in Victoria Hospital. Others were found in the vagina of another patient. Out of the four patients attacked, two occupied the same bed, one after the other, and a third the next bed to it. The other case was in a more remote part of the hospital. There are numerous records of this fly attacking man. It occurs from the Argentine to Texas.--F. V. T.]

*Chrysomyia viridula*, Rob. Desv.

[This species is somewhat larger than the former; the body is metallic bluish-green, the dorsum of the thorax with three blackish, longitudinal stripes, and the face ochraceous; about 10 mm. long. Austen records this species from man, Dr. Daniels having bred it from larvæ from a sore on a human being in New Amsterdam, British Guiana. Dr. Laurence also bred it in Trinidad. In the latter case between 100 and 150 maggots were discharged from the nose of a woman suffering from facial myiasis (Brit. Med. Journ., January 9, 1909, p. 88 + fig.).--F. V. T.]

Genus. *Lucilia*, Rob. Desv.

*Lucilia nobilis*, Meig.

The larvæ were observed by Meinert in Copenhagen in the auditory meatus of a person who, after taking a bath, fell asleep in the open air, and on waking felt singing in the ears, and had a sensation as if there were water in the auditory canal. During the next days severe pains set in, and there was a discharge of blood and pus from both ears, as well as from the nose. On washing out the meatus the maggots made their appearance.

Lucilia cæsar and L. sericata have also been observed in the larval state in man (Thompson, Hope, Henneberg and Calendoli, Napoli, 1907).

[This golden-green fly usually lays its eggs on decomposing organic matter; now and again it lays its eggs in wounds on man.--F. V. T.]

Genus. *Pycnosoma*, Brauer and v. Bergenstamm.

The species of this genus have a general resemblance to the Lucilias and Chrysomyias, but the body is stouter and the abdomen banded. The genus can be distinguished from Chrysomyia by the absence of the three thoracic stripes and by the eyes of the male, in which the facets forming the upper portion are much enlarged, whereas in Chrysomyia they are not noticeably larger. Austen also points out that the sterno-pleural bristles in Pycnosoma are 1 : 1, in Chrysomyia 2 : 1. The genus is found in tropical Asia and Africa only. All records of Chrysomyia (Compsomyia) in India must be referred to this genus. Bezzi and Stein (“Katalog der Palăarktischen Dipteren,” 1907, iii, p. 543), however, regard the two as synonymous.

The larvæ are frequently found in the nostrils of man and burrow into the sinus, but normally they live on decaying animal matter.

Pycnosoma forms the so-called Indian screw-worm. Patterson (Ind. Med. Gaz., October, 1909, xliv, No. 10) records the case of a woman at Tezpin, Assam, from whom as many as 100 larvæ were removed at one time, and later the left orbital cavity was found packed with hundreds of maggots; eventually the patient died. It is possible that this, however, was due to a species of Sarcophaga. Austen undoubtedly records this genus causing nasal myiasis in India (Trans. Soc. Trop. Med. and Hyg., iii, p. 235). At Dehra Doon, U.P., a woman discharged 100 larvæ from her nose, with great pain in the nasal region and frontal sinuses.

The so-called “peenash,” a common malady in Rajputana, is a true nasal myiasis.

Genus. *Sarcophaga*, Mg.

*Sarcophaga carnosa*, L., 1758.

Larvæ of flesh-flies provided with two claws at the anterior end, which settle on raw or cooked meat, and in the open on carcases of animals; they are often observed in man, both in the intestine (introduced with food) and in the nasal cavities, frontal sinus, conjunctiva, aural meatus, anus, vulva, vagina, prepuce, and open ulcers, often migrating further from the regions first attacked. (Gayot in Compt. rend. Acad. Sci., Paris, 1838, vii, p. 125. Grube in Arch. f. Naturg., 1853, xix, 1, p. 282. Legrand du Saulle in Compt. rend. Acad. Sci., Paris, 1857, xlv, p. 600, and other authors.)

[This fly is viviparous. The fly varies from 10 to 30 mm. in length, and is of a general ash-grey colour; the thorax with three dark stripes, the abdomen light grey with three black spots on each segment; legs black; base of wings yellow. It also attacks animals and birds, especially geese. The genus Sarcophaga is universally distributed. The maggots are whitish or yellowish footless larvæ of twelve segments, tapering to a point in front, broadened posteriorly. There are two mouth hooks, by means of which they rasp their food. The breathing pores are at the end and consist of two groups of three slits, each surrounded by a hardened area. They pupate in their old skin, which turns brown.--F. V. T.]

*Sarcophaga magnifica*, Schiner, 1862.[412]

Syn.: Sarcophaga wohlfahrti, Portschinsky, 1875.

[412] [The correct name for this fly is Wohlfahrtia magnifica, Schiner.--F. V. T.]

A species widely distributed over the whole of Europe, occurring especially in Russia (Mohilew); the presence of the larvæ in man was first observed by Wohlfahrt (1768). The larvæ settle in the pharynx, in the nose, the aural meatus, the conjunctiva, and in other regions of the human body; they also attack domestic animals and birds. As Portschinsky has shown, they cause severe inflammations, hæmorrhages and suppurations in the organs in which they occur; children are especially attacked. A number of cases have been observed also in Central and Western Europe. [The fly has a light grey abdomen with shiny black spots which do not change their shape and appearance according to the angle in which the fly is viewed.--F. V. T.]

(Wohlfahrt: “Observ. de vermibus per nares excretis,” Halæ, 1768; Nov. Act. Acad. Caes. Nat. curios., 1770, iv, p. 277. Gerstäcker in: Sitzungsb. Ges. nat. Frde. Berl., 1875, p. 108. Portschinsky in: Horæ soc. entom. ross., 1875, 1884, p. 123. Laboulbène in: Ann. Soc. ent. France, 1883 (6), iii; Bull., p. xcii. Leon in: Bull. Soc. des Méd. et Nat. de Jassy, 1905, xix, p. i. Freund, L., in: Verh. Ges. deutsch. Naturf. u. Ärzte, Homburg (1902), 1902, ii, 2, p. 450, and other authors.) [Probably most cases of attack in Europe are due to this species.--F. V. T.]

The above cited do not exhaust the number of observations of diptera larvæ parasitic in man; there are yet to be mentioned the larvæ of S. hæmorrhoidalis, S. hæmatodes (of G. Joseph), those of S. ruficornis (excitants of a cutaneous myiasis in the East Indies), those of species of Eristalis (of Hanby and others), and those of Phora rufipes (of Kahl, of Warsaw, and others). In many cases the determination of the diptera larvæ has been omitted (or must be omitted); such is the case with diptera larvæ in the eye (Schultz-Zehden in: Berl. klin. Wochenschr., 1906, p. 286. Ollendorf in: Med. Korrespondenzbl. d. würt. ärtzl. Landesver., 1904, p. 1017. Kayser in: Klin. Monatsbl. f. Augenheilkunde, 1905, xliii, i, p. 205. Ewetzky and v. Kennel in: Zeitschr. f. Augenheilkunde, 1904, xii, p. 337, and other cases). Austen records several cases of myiasis due to Sarcophaga (vide Trans. Soc. Trop. Med. and Hyg., 1910, iii, No. 6).

The larvæ of African Muscidæ have now become of greater interest; like several Oestrid larvæ they live normally in the skin of mammals, but also attack man. The knowledge of these species is certainly very insufficient, but this is not likely to be the case much longer, as medical men practising in the Colonies are giving their attention to these parasites. At the present time four distinct forms are recognized according to Gedoelst.[413]

[413] [The following are known to cause myiasis in man in Africa: Cordylobia anthropophaga, Grünb.; Auchmeromyia luteola, Fabr.; A. rodhani, Gedoelst; Oestrus ovis, Linn.; and Anthomyia desjardensii, Macq. The anthropophaga, Blanchard, and the depressa, Walker, referred to here are Grünberg’s anthropophaga.--F. V. T.]

*Sarcophaga chrysotoma*, Wied.

[This species is recorded as attacking human beings at New Amsterdam, British Guiana. The fly is 15 mm. long, has a golden-coloured face, three broad black thoracic stripes and ochraceous buff anal segments. It was bred from larvæ obtained by Dr. Roland from a sore on a girl’s foot. It is known to occur in the Brazils and the West Indies. Another species was also bred which Austen was unable to identify.--F. V. T.]

*Sarcophaga plinthopyga*, Wied.

[This and other species of Sarcophaga are called “yaw flies” in Dominica, as they are believed to be concerned in the dissemination of frambœsia or yaws (Nicholls) (vide Austen, Trans. Soc. Trop. Med. and Hyg., 1910, iii, p. 239).--F. V. T.]

*Ochromyia anthropophaga*, E. Blanch.; *Cordylobia arthrophaga*, Grünberg.

Indigenous to the Senegal and neighbouring districts; in the district of Cayor (between the mouth of the Senegal and Cape Verde) the larva is known as the “ver de Cayor.” It lives under the skin, especially at the lower extremities and the lower region of the trunk, producing small boils, which cause pain, but after about eight days, when the larva leaves the body to enter the pupal stage, the pain discontinues. Besides man the larva occurs in dogs, goats, cats, and in the jackal. It is still questionable whether the fly deposits its eggs direct or on the ground, from whence the larvæ as they emerge gain access to animals and man. Larvæ yellowish-white, 14 mm. long, 4 mm. wide, eleven segments[414]; head with two globular antennæ-like appendages, two black curved mouth hooks, and two wart-shaped, finely spinous structures at their base. Body evenly covered to the seventh segment with small black prickles, which are stronger at the sides and the anterior borders of the segments; from the seventh they increase in size, on the two hindermost they are wanting; on the last segment two deep yellow spiracles, each with three markedly curved fissures; in addition two stigmata on the posterior border of the first segment. Duration of the larval stage about eight days. Upon the construction of roads in Guinea the larva is spread by dogs far into the interior.

[414] [Austen gives the length as 12 to 12·5 mm. and the breadth as 5 mm.; he describes the larva as follows: Bluntly pointed at the anterior extremity, and truncate behind; from third to eleventh segments thickly covered with minute recurved spines of brownish chitin, usually arranged in transverse series of groups of two or more, which can be seen to form more or less distinct undulating and irregular transverse rows. In each of the two posterior stigmatic plates, the respiratory slit on either side of the median one is characteristically curved, resembling an inverted note of interrogation. The barrel-shaped puparium is on an average 10·3 by 4·6 mm.; its colour varies from ferruginous to nearly black.--F. V. T.]

*Auchmeromyia* (*Bengalia*) *depressa* (Walker).[415]

[415] [According to Austen this is Cordylobia anthropophaga, Grünb. Bengalia depressa, Walker, is a very different insect, whose life-history is unknown.--F. V. T.]

Distributed in the region of Natal and apparently over the whole of South Africa. The “larva of Natal,” as one may still term the species provisionally, as its identity is not certain, possesses on its head (besides the mouth hooks) lateral protuberances beset with a row of chitinous spines. The cuticle of the body is spinose. The spines are difficult to recognize on account of their transparency and want of colour; they are longest over the anterior segments, from the fifth they become smaller, and over the hindermost they are very small. Apart from the foremost segment, the position they take is that of rows running transversely or obliquely, two to four generally in juxtaposition; the number of spines in the groups gradually increases posteriorly, attaining the number of eight to twelve on the sixth segment, and this number is maintained to the end of the body. Isolated spines are found over the head; over the second, third and fourth segments single ones are still found adjoining the groups of spines, from the fifth onward they are wanting. From here the spines cover the whole free surface of the segments; over the fourth the anterior three-quarters, over the third two-thirds and over the first and second only the anterior half. The stigmata found at the anterior end also serve as distinguishing characters. The parasitic stage appears to last about fourteen days. [Fuller (Agric. Journ., Dept. Agric. and Mines, Natal, 1901, iv, p. 606) refers to this as Bengalia depressa also.--F. V. T.]

Genus. *Cordylobia*, Grünberg, 1903.

*Cordylobia grünbergi*, Dönitz.

Syn.: Ochromyia anthropophaga, Grünberg, nec Blanch.; Cordylobia anthropophaga, Grünberg.

Endemic in German East Africa and neighbouring regions. Larva up to 14 mm. long, 4 to 5·5 mm. wide, of cylindrical shape, slightly narrowed behind, truncated, gradually tapering in front; antennæ-like processes, cone-shaped, blunt. Smaller cylindrical formations at the base of the mouth hooks surrounded by a circle of chitinous hooks. Body from the first segment covered with small brown squamous spines which are disposed in numerous irregular transverse rows. The spines are small over the two first segments, the two posterior thirds of all the segments, as well as from the eighth; over the third to the seventh they are larger, but between these there are very small spines. The breathing pores of the stigmata at the anterior end are kidney-shaped; the orifices are elongated and very tortuous, each divided into three. The larval period appears to last several weeks.

*Cordylobia anthropophaga*, Grünberg.

This well-known cutaneous African parasite seems to have been the cause of much confusion in regard to names. It belongs to the genus Cordylobia of Grünberg, and is one of the family Muscidæ, and differs from Auchmeromyia in that the second abdominal segment of the female is of normal size, whilst in Auchmeromyia it is more than half the length of the whole abdomen, and in the male the eyes are holoptic or close together, whilst in Auchmeromyia they are wide apart. The flies of this genus (three so far described) attack man in their larval stage (anyway two of the three), and also dogs and other animals, by burrowing into the skin and producing painful boils.

[C. anthropophaga, Grünberg, is widely distributed in Africa, extending from Senegal, where its maggot is known as the “ver de Cayor,” and is referred to on p. 590 as Ochromyia anthropophaga, E. Blanchard, to Natal, where it is known as the “Natal worm,” and referred to erroneously on p. 591 as Bengalia depressa, Walker.

[It is a thick-set Muscid of a general straw-yellow colour, with blackish markings on the dorsum of both thorax and abdomen, about 9·5 mm. long. The larva is fat and when mature about 12 mm. long, bluntly pointed in front, truncate behind; from the third to eleventh segments it is thickly covered with minute recurved spines of a brownish colour, arranged in transverse series of groups of two or more, which form more or less distinct irregular transverse rows. On each of the two posterior stigmatic plates, the respiratory slit on either side of the median one is characteristically curved, resembling an inverted note of interrogation. The puparium is brown to ferruginous or black and about 10 mm. long. The maggots are found in both natives and white men, and occur as a severe pest in dogs, also in monkeys, rats, and other mammals. In Sierra Leone it is called the “tumba fly.” The larvæ have been frequently found as true subcutaneous parasites, each larva living singly and forming a boil or warble in the skin, with an opening just as in an ox-warble, through which the maggot breathes and eventually escapes. Although they more usually occur as isolated specimens, Marshall found in Salisbury, South Rhodesia, that sixty were extracted from one lady, and Bérenger-Féraud, in Senegal, that more than 300 occurred in a single spaniel puppy.

[Neave (Bull. Ent. Res., 1912, iii, p. 217) records it from ulcers in a native at Lourenço Marques in 1908, and at the same time from ulcers in a dog, and that it is a severe pest to man in Mozambique and parts of the Transvaal. It seems to be more abundant in North Rhodesia and Nyasaland than to the north (Neave, Bull. Ent. Res., 1912, iii, p. 310). It is also recorded in Zanzibar, German East Africa, Uganda, East Tropical Africa (Neave).

[Simpson (Bull. Ent. Res., iii, p. 170) records a Muscid larva taken from the breast of a European in South Nigeria that was probably Cordylobia.

[It is not known how infection takes place. Neave (Bull. Ent. Res., iii, p. 310) says: “Many instances in human beings would preclude the possibility of eggs having been laid direct on the skin: in these cases they have probably been laid on the clothing put out to dry.”

[Gedoelst has described another species, C. rodhani, and Austen a third species, C. prægrandis, from Nyasaland, Cape Colony, Transvaal, Natal, North-west Rhodesia, and German East Africa.

[The following are some papers dealing with this subject: Proc. Ent. Soc., London, for year 1907, p. xlvii; Journ. R.A.M.C., 1908, pp. 5–11, figs. 1 and 2, by Austen; Journ. R.A.M.C., 1908, pp. 1 and 2, by Major F. Smith; Trans. Soc. Trop. Med. and Hyg., 1910, iii, pp. 223–225, by Austen.--F. V. T.]

*Lund’s Larva.*

Endemic in the region of the Congo State; called after Commander Lund, from the skin of whose arm it was extracted; 12·5 mm. long, 4·5 mm. broad; colour yellowish, with brown rings, on account of the division of the brown spines; head cone-shaped, with two hemispherical smooth antennæ, two thick black mouth hooks and wart-shaped bodies, between which are situate two to three longitudinal rows of dark brown chitinous laminæ. The body segments are covered over their whole surface with irregularly distributed triangular yellow spines, the points of which are coloured dark brown. Its size increases from the second to the sixth segment, diminishes from the seventh to the ninth, at the tenth it is reduced, and at the eleventh quite small. The posterior stigmata are bean-shaped, each with three markedly tortuous openings. Duration of the larval stage unknown; the same applies to the pupal and imago stages.

*Auchmeromyia luteola*, Fabricius.

[This fly, the parent of the so-called Congo floor maggot,[416] belongs to a nearly allied Muscid genus to Cordylobia, but which can at once be told by the great length of the second abdominal segment. The maggot occurs in numbers in the native huts in the Congo region and is fairly common in central and northern parts of Mozambique; it is also recorded from the Zambesi River and the vicinity of Barberton in the Eastern Transvaal (Bull. Ent. Res., 1912, iii, p. 216), in German East Africa, in Nyasaland, and British East Africa. It is also recorded from Bara, Kordofan,[417] where they occurred on the floor of the men’s prison and bit the prisoners. They were destroyed by sprinkling Jeyes’ fluid on the floor. Neave states (ibid., p. 310) that it occurs in the more neglected huts in native villages throughout tropical Africa, and frequently enters a tent when pitched near a village. It is also found in West Africa. The fly is thick-set and about the size and build of a bluebottle fly; length 10 to 12 mm.; tawny in colour to dirty yellowish-brown, with dusky hairs, giving it a smoky appearance; the flattened thorax has long dark stripes and the abdomen a dusky line in the centre of the second segment, which meets a dark line on its posterior border; the dusky third segment has a narrow yellowish anterior line; the fourth segment is also dusky; legs buff with black hairs; the fifth tarsal segment black. The larvæ are whitish, becoming reddish after a feast of blood, with much wrinkled skin and rather flat and broad. They live in crevices of the mud floor, under sleeping mats during the daytime, and come out at night and suck the blood of sleepers and then retire to shelter again. Dutton, Todd, and Christy noticed that where people slept on beds or platforms raised above the floor the maggots were not so numerous as under the sleeping mats laid on the ground. They turned up many of the maggots from a depth of three inches or more.[418]--F. V. T.]

[416] Dutton, Todd and Christy, “The Congo Floor Maggot,” _Mem. xiii Liv. Sch. Trop. Med._, p. 40.

[417] Balfour, Journ. Trop. Med., 1909, xii, No. 4, p. 47.

[418] Journ. Trop. Med., 1905, viii, No. 6, p. 90.

Family. *Oestridæ.*

[The family of Oestridæ or warble flies are all parasitic in their larval stage, usually termed the “bot” stage. They are found as parasites in warm-blooded animals, and man is frequently attacked by them. The members of this family have the mouth rudimentary, many of them are hairy and bee-like, with large eyes and the head large, the lower part more or less swollen. The thorax is large with a distinct transverse suture, and the abdomen short and stumpy or very slightly elongated. The male genitalia are hidden, whilst the female ovipositor is often elongated. The wings may be transparent (Hypoderma) or mottled (Gastrophilus), and have muscid-like venation; the tegulæ usually large, the legs moderately long.

[As a rule each species is confined to a particular host, but as we see recorded here those that attack animals may also attack man. The flies occur in warm weather and usually during the warmest part of the day, and have a strong dislike to shade and water. The genus Hypoderma attack oxen, sheep, goats, antelope and musk deer; Oestrus, sheep, antelope and horses; Gastrophilus, the horse and ass; Cephenomyia, the deer; Cepholomyia, the camel and buffalo; Dermatobia, dogs, cats, oxen, deer, apes and man; Cuterebra and Rogenhofera, rodents and opossums.

[Some live as parasites in the stomach and intestines (Gastrophilus); others infest the skin (Hypoderma, Dermatobia and Oestromyia, the latter on Lagomys and Hypodæus); Œdemagena tarandi also infests the skin of the reindeer in Siberia and boreal America. Oestrus lives in the nasal sinus, and Cephalomyia in the throat as well, Cuterebra and Rogenhofera, the skin or scrotum, so that we have really three groups of parasitic oestride larvæ: (i) cutaneous, (ii) intestinal, and (iii) facial.

[No species seems confined to man, but the so-called “creeping disease,” caused by Hypodermæ, and the attack of sheep nasal fly are comparatively common, as also is the Dermatobia attack.--F. V. T.].

CUTANEOUS OESTRIDÆ.

The eggs are deposited on the surface of the body; the larvæ burrow in the skin, which they reach after somewhat long peregrination.

Genus. *Hypoderma*, Latreille.

*Hypoderma bovis*, de Geer.

The cattle fly or warble fly, which swarms during the hot season, settles on the head or on the hair of grazing cattle: through the young being licked off they gain access to the mouth and are swallowed.[419] The larvæ appear first in the commencing portion of the stomach, to escape, as some state, into the preceding sections of the alimentary canal; at any rate, they are found from July onward regularly in the submucous tissue of the pharynx, in which they travel about for several months (up to November, and in isolated cases up to February); they then penetrate the muscularis and migrate by way of the subserosa along the mediastinum, the crura of the diaphragm, the renal capsules, and the intermuscular connective tissue of the psoas muscle in the direction of the spinal canal, into which they penetrate by way of the muscles and nerves, through the intervertebral foramina. Here they stay for about two to three months, then they leave the spinal canal again through the vertebral foramina and make their way (from January to March) through the intermuscular connective tissue of the muscles of the back to the skin of the back, where sooner or later (from January to June) they arrive and enter a resting stage, which commences with penetration of the skin and terminates with outward migration from the boils due to the wound set up by the maggot. At the commencement of this period the larvæ cast their skin, and their form, hitherto cylindrical, becomes oval. After about a month, a second moulting of the skin takes place--the third larval stage, which lasts about two and a half months (up to June). The approaching end of the same is indicated by a change of colour on the part of the larva from the hitherto yellowish-white to brown and finally to blackish-brown. When they have become mature the larvæ leave the warbles, drop on to the ground and pass into the pupal stage in the superficial layers of the soil within twelve to thirty-six hours. After about a month the flies emerge. Irregularities with regard to the time and direction of the migrations of the larvæ take place (Jost, H., in Zeitschr. f. wiss. Zool., 1907, xxxvi, p. 644).

[419] [This is not the case, for Carpenter has shown that muzzled calves become infected (“Mém. First Int. Cong. Ent.,” pp. 289–293). Jost (Zeitschr. f. wiss. Zool., 1907, xxxvi, pp. 644–715) thinks that the ova, not young larvæ, are ingested (vide note in Supplement).--F. V. T.]

In a number of cases the larva of the cattle fly has been observed in the human integument, usually in the winter months, that is, during the migration period; consequently, it is not surprising that the larvæ before they enter on the resting stage and produce a warble undergo migrations. But that this takes place subcutaneously--which does not appear to be so in the case of cattle--is perhaps explained by the fact that in man, on account of the short space that has to be traversed, the larvæ are not sufficiently developed to enter on the resting stage simultaneously upon having obtained access to the integument. Whether the Oestrid larvæ in Bulgaria that similarly migrate beneath the skin in man belong to the cattle fly or to another species, or even another genus, has not yet been ascertained. (Doctorow, in Arch. de Par., 1906, x, p. 309; Spring, A., in Bull. Acad. sci. Belg., 1861 (2), iv, p. 172; Walker, R., in Brit. Med. Journ., 1870, i, p. 151; Kjelgaard, in Ugeskr. f. Laeger, 1904, p. 535; Condorelli, M., in Bull. Soc. Zool. Ital., 1904, xiii, p. 171.)

*Hypoderma lineata*, de Villers.

The larvæ of this species, that occurs not only in Europe but in North America, live under similar conditions in the skin, very rarely in man; also migrating subcutaneously (Topsent in Arch. de Par., 1901, iv, p. 609).

[In Sweden, the ox warble fly (H. bovis) is well known to attack man. Schoyen states “that over 100 years ago up to the present time cases of travelling grubs under the human skin in some districts of Sweden were well known.” The species appeared to be H. bovis, many of which he had examined. They accomplished long ramblings under the skin, always in an upward direction, previous to their appearance through an opening in a tumour on the upper part of the body, on the head, neck, or shoulders. An interesting case is recorded in Insect Life, ii, pp. 238–239. A bot similar to H. diana was taken from the eye and cheek of a child at Kane, McKean County, Pa., U.S.A. It was said to have travelled in five months from the elbow to the eye. Riley later (Insect Life, iv, p. 310) was inclined to think the maggot was that of H. lineata, the common American ox warble, which is also found in Europe in great numbers. I have recorded another case in England (Rept. Econ. Zool. for year ending September 30, 1910, p. 128), where Dr. Menzies removed the larva of H. bovis from the upper eyelid of a patient. It caused considerable swelling of the face, much pain and distress; but the case did well, and the wound healed at once. The larva was nearly mature. Numerous other references to this so-called creeping disease will be found in the Supplement.

[It is quite probable that bovis and lineata are confused in the latter accounts. The larvæ are, however, easily distinguished if carefully examined.--F. V. T.]

*Hypoderma diana*, Brauer.

In its larval stage it lives like other species of Hypoderma, attacking the red deer (Cervas elaphas) and roe deer (Cervas capreolus); it is occasionally also found in man (Joseph, in “Myiasis externa dermatosa,” Hamburg, 1800; Völkel, in Berl. klin. Wochenschr., 1883, xx, p. 209).

Genus. *Dermatobia*, Brauer.

*Dermatobia cyaniventris*, Macq.

Syn.: Dermatobia noxialis, J. Goudot.

The genus Dermatobia represents the subcutaneous Oestridæ of Europe in warmer parts of America. Both domesticated and wild mammals are attacked, according to one statement birds also (Ramphastus), and man with fair frequency.[420] It is assumed that in all cases one and the same species is concerned, for which recently a name originating from C. Linné, jun. (Oestrus hominis), has been employed. Three larval stages are recognized in the skin; the two first appear to resemble one another in the club-shaped or tadpole-like appearance (called macaque in Cayenne, mayacuil [mayoquil] in Mexico), the third is swollen spindle-shaped (Berne, called torcel). Segments 2 to 4 in the club-shaped larvæ are closely beset with small black spines, segments 5 to 7 bear at the anterior border a complete ring of strong black hooks, segments 4 to 6 a similar ring, which, however, is interrupted at the ventral surface. The four last segments forming the tail are smooth, only at the posterior end are there small spines. The arrangement of spines of the third stage differs from this. Italian workmen that have been employed in Brazil show the presence of Dermatobia larvæ on their return (Blanchard, in Bull. Soc. Ent. France, 1893, p. 24; Bull. Soc. centr. de Méd. vet., 1896; Ann. Soc. Ent. France, 1894, lxiii, p. 142; Ward, H. B., in Mark Annivers. Vol., Article 25, p. 483, New York, 1903).

[420] Duprey advances the opinion that Dermatobia deposits its eggs not only on the skin of man and animals, but also on the leaves and twigs in the bush, where, too, young larvæ have been met with which gain access from hence to men and animals (Journ. Trop. Med. and Hyg., 1906).

[Dermatobia cyaniventris, Macquart, 1843, is said not to be the same as noxialis (vide Brauer, “Mono. Oestriden,” 1863, p. 266). It is known by various other names, as nuche or gusano in New Granada, the ura in Brazil, and the macaw fly in Cayenne. It occurs in Central and South America and the West Indies. According to Goudot the fly is found in great numbers on the borders of large woods and lands covered with underwood.

[It is seldom that more than one larva is found in each individual. It is generally found in the arm and leg, but now and then the face. The perfect insect has never been bred from a larva removed from a human being, so that there is still uncertainty as to the actual species. D. cyaniventris is 11 to 12 mm. long, has an ochraceous buff-coloured face, dark grey thorax, metallic dark blue to purple abdomen, and brownish wings. D. noxialis is somewhat larger.

[In the Journal of Tropical Medicine and Hygiene, January 15, 1905, viii, p. 23, reference is made to this Oestrid in Trinidad, where it is called the “mosquito worm.” One case here recorded showed no fewer than four worms on the chin and one on the hand. It is here stated that the fly never attacks man or animals directly, as it is said to do by Scheube, but that the eggs are deposited on leaves and branches in wooded lands and forests, and thus man, hunting dogs and wild animals in passing through get the larvæ deposited on them accidentally. The affection is common in Trinidad. Mention is made that a little 1 in 40 carbolic lotion syringed into the aperture in the skin over the worm quickly killed it.

[The cattle worm, or founzaia ngómbe, is the name given to a larva which develops beneath the skin of oxen and men in Central Africa, especially amongst the natives and stock of Unyamonezi. According to P. Dutrieux, the egg is laid by a large fly that accompanies cattle. It is unknown between the central plateau or the Ugogo and the East Coast.--F. V. T.]

CAVICOLOUS OESTRIDÆ.

The forms belonging to this group inhabit as larvæ the nasal and frontal sinuses of ruminants, Equidæ and Proboscidæ, which they leave for the pupal stage. The larva of--

Genus. *Oestrus*, Linnæus,

*Oestrus* (*Cephalomyia*) *ovis*, L.,

occurring in sheep, has also been observed in man in six cases in the nose and larynx (Saitta in Gaz. d. Osp. d. Clinic, 1903, No. 128). So far as is known, the eggs are deposited in the nasal cavity.

[Oestrus ovis frequently occurs in man. MM. Sergent (Ann. de l’Inst. Pasteur, 1907, pp. 392–399) mention that they lay their ova on the noses, eyes and mouth of humans in Algeria whilst flying, but that they disappear after three to ten days or the inflammation produced by them. Portschinsky (Mem. Bur. Ent. Sci. Com. Cent. Bd. Land Adm. and Agric., 1913, x, No. 3, p. 63) also gives cases. He doubts that ova are laid on the nose; evidently the Russian habit is anomalous, for the Sergents, Collings and myself find ova laid as a common occurrence. I have often seen them on the nose of sheep. This fly also occurs in the Argentine (Serres, in Gaceta Rural, April, 1913, vi, pp. 759–761).

[The tamné or thimni of the Kabyles, a human myiasis of the Tuareg mountains in the Sahara, is caused by Oestrus ovis. Here the larvæ are said to be ejected on to the conjunctival and nasal mucous membrane of humans.

[Ed. and Lt. Sergent (Bull. Soc. Path. exot., 1913, vi, No. 7, pp. 487–488) report their attack from the Ahaggar mountains, in Central Sahara. The Tuareg name for the fly, tamné, is the Targui form of the word thimni used by the Kabyles.--F. V. T.]

GASTRICOLOUS OESTRIDÆ.

The eggs are deposited on the hairs of Equidæ, and the larvæ escaping from them are licked up and swallowed. They pass their larval stage, according to the species, in various parts of the intestine and stomach, and when mature, pass out per anum in order to undergo the pupal stage.

Genus. *Gastrophilus*, Leach.

One of the most frequent species is Gastrophilus equi, Fabr.; the eggs are laid on the hairs; the larvæ live some ten months in the stomach, living attached to the inner surface. The eggs of G. hæmorrhoidalis, L., are deposited on the lips or the long hairs on them. The larvæ adhere to the cardiac end of the stomach, to the stomach itself, and finally to the terminal portion of the intestine. Here, however, and elsewhere in the intestine, the larvæ of G. pecorum, Fabr., are also met with, whilst the larvæ of G. nasalis (so called because the eggs are deposited in the nasal orifices) almost exclusively inhabit the anterior section of the duodenum.

Cholodkowsky attributes the “wormlet” observed by Samson and Sokolew (Wratsch, 1895, Nos. 48 and 57) and others (ibid., 1896–98) to Gastrophilus larvæ. It burrows into the epidermis of man by minute passages. This observation should, however, be verified. The phenomenon is designated as skin-mole, larva migrans, and creeping eruption.

OTHER PAPERS ON DIPTEROUS LARVÆ, ETC., IN MAN.

(1) “Ein Fall von lebenden Fliegenlarven im menschlichen Magen,” Deutsch med. Wochenschr., Leipz. and Berl., xxiv (12), pp. 193–194. Bachmann, and review of same, “Living Fly Larvæ in the Human Stomach,” Philadelphia Med. Journ., 1898, i, 18, p. 773.

(2) “Sudi una larva di dittero parassita della congiuntiva umana,” Ann. di ottal., Paira, 1895, xxiv (4), pp. 329–336, 1 fig., E. Baquis.

(3) “Sur quelques diptères suceurs de sang, observé à Terre-Neuve,” Arch. de Par., Paris, 1900, iii (1), pp. 202–204, E. Barret.

(4) “An Account of the Larvæ of two Species of Insects discharged from the Human Body,” Edin. Med. and Surg. Journ., January 1, 1811, vii (25), pp. 41–48, 1 pl., figs. 1 to 8, T. Bateman.

(5) “Un cas de myiase par la Sarcophaga magnifica en Roumanie,” Bull. Soc. Zool. de France, Par., 1891, xvi (2), pp. 25–26, R. Blanchard.

(6) “Sur les oestrides américains dont la larve vit dans la peau de l’homme,” Ann. Soc. ent. de France, 1892, v, pp. 109–154, figs. 1–12, R. Blanchard.

(7) “Note additionnelle sur les oestrides américans dont la larve vit dans la peau de l’homme,” Bull. Soc. ent. de France, Paris, 1894, xiv, pp. 209–211, R. Blanchard.

(8) “Note sur des larves de Dermatobia provenant de Brésil,” Bull. Soc. ent. de France, Paris, 1893 (2), pp. 24–27, R. Blanchard.

(9) “Larven der Wohlfahrtfliege (Sarcophila wolfahrtii) im Zahnfleische eines Menchen,” Wratsch., St. Petersburg, 1888, 5–6, E. K. Brandt.

(10) “Ueber den sogenannten Oestrus hominis und die oftmals besichteten Verirrungen von Oestriden der Säugetheiere zum Menchen,” Verhandl. d. k. zool.-bot. Gesellsch., 1860, x Abhandl., pp. 57–72, Brauer.

(11) “Ueber die Larven der Gattung Cuterebra, Clk.,” Verhandl. d. k. zool.-bot. Gesellsch., 1860, x Abhand., pp. 777–786, Brauer.

(12) “Des désordres produits chez l’homme par les larves de la Lucilia hominivorax,” Thèse, Paris, 1864, 43 pp., V. Audouit.

(13) “Note on the ‘Flesh Worm,’” Med. Press and Circ., London, April 12, 1882, lxxxii (N.S. xxxiii), p. 314, P. S. Abraham.

(14) “Larvas de la Calliphora limensis en fosas nasalis,” 1855, 18 pp., F. Aguirre.

(15) “Raro caso di parasitismo nell ’uomo dovuto alla larva di una mosca (Sarcophaga affinis, Meigen),” Boll. d. Soc. Rom. per gli Stud. Zool., Roma, 1893, iv (5–6), pp. 278–289, 1 pl., 3 figs., Giulo Alessandrini.

(16) “Observations sur l’espèce de ver nommé Macaque (Oestrus),” Mém. Acad. Sci. par Hist., 1753, p. 72, F. Artur.

(17) “Contribuição ao estudo da biologia da Dermatobia cyaniventris,” Trav. do Inst. de Manguinhos, 1908.

BITING-MOUTHED AND OTHER NOXIOUS DIPTERA WHICH MAY BE DISEASE CARRIERS.

[Amongst the division Brachycera (as meant in this work) we get several groups of flies which, like the fleas and mosquitoes, are partially parasitic on man, the adults, mainly in the female sex, being provided with a piercing mouth with which they extract the blood of man and animals. The importance of these parasites is not the mere fact that they feed upon our blood, but that they often carry germs from man to man (tsetse-flies and trypanosomiasis, Tabanidæ and anthrax). Amongst the most important biting-mouthed Diptera in this section are the following: Tabanidæ, or gad-flies; Glossinæ, or tsetse-flies; and certain other Muscidæ. Some of the exotic Asilidæ and a few Leptidæ also bite man.

Family. *Tabanidæ* (Gad-flies).

[The Tabanidæ have a broad, rather flattened body and a large head; eyes united in the male (except in some Chrysops). The antennæ are composed of three segments, have the third joint composed of five to eight annuli--in Chrysops they are fairly long. The proboscis is projecting, and sometimes much elongated. The legs are moderately stout. The venation of the wings is shown in fig. 415.

[This family of gad or horse flies contains a great number of genera, all of which may bite animals and man more or less severely. The female alone is blood-sucking, the males feed upon the juices of flowers. The females deposit their spindle-shaped white, black, or brown eggs on leaves, stems of plants that either overhang or stand in water, and amongst rushes; they are at first white, but become brown or black. The eggs are laid in rounded, flattened or conical masses composed of layers one upon the other. The larvæ are carnivorous, feeding upon snails, worms, other larvæ, etc., and have a distinct head; they are cylindrical, composed of eleven segments, the last with a vertical breathing pore, or the last two segments may form a breathing tube. The majority taper to a point at each end, in colour shining white or dull grey to yellowish, many of the larger specimens mottled or banded with dark brown or black. The first seven abdominal segments are encircled near the anterior margin with a ring of fleshy protuberances consisting of a transverse dorsal ridge which may be divided by a depression into two. The young larvæ burrow into any soft vegetable substance; they live both in the water and under damp soil surrounding water, also in damp earth generally. The larvæ are not only carnivorous, but they are cannibals, frequently devouring their own species. They may take more than a year to mature.

[The pupæ are found close to the surface of mud and earth, and are mostly dull yellowish to brown in colour, with rows of spines on the distal third of each abdominal segment; the thorax bears a pair of ear-shaped spiracular structures, and there are also six denticles at the apex of the abdomen.

[A habit common to the adults of most of the Tabanidæ of considerable economic importance is that of the adults coming to water to drink. Portschinsky[421] has found that by applying kerosene to the pool they frequent the adults are killed, and Hine[422] that the same oil kills the larvæ that fall into the water from eggs laid on plants above.

[421] Vide Bull. 20, N. Sc., U.S. Div. Ent.

[422] “Tabanidæ of Ohio,” Ohio State University Bull. 19, 1903, sec. 7, p. 14.

[Tabanidæ are not only of importance as purely biting insects, for they may often convey pathogenic organisms from one animal to another, such as the bacillus of anthrax, which they are known to carry, and possibly also trypanosomes in regard to man. Chrysops also acts as a host of Filaria loa in South Nigeria (Leiper, Brit. Med. Journ., January, 1912, pp. 39–40). Two species are incriminated, viz., C. silacea and C. dimidiata. With animals these flies play a more important part, for MM. Sergent, in Algeria, have proved that species of Tabanus are able to transmit three forms of animal trypanosomes by biting a healthy animal as long as twenty-two hours after having bitten an unhealthy one. In India they have also been shown to transmit the parasite of “surra” in dogs and rabbits by Rogers. Other observers have since corroborated these results, and Mitzmain, who has recently performed valuable work in this connection, states that T. striatus is undoubtedly the carrier of this disease in the Philippine Islands. Certain members of the genus Hæmatopota have also been shown to be capable of the direct transmission of Trypanosoma evansi. Martoglio (Ann. d’Ig. sper., 1913, xxiii, N.S., No. 3, pp. 363–366) states that the trypanosome disease of dromedaries known as salaf is transmitted by Tabanidæ, especially Pangonia (P. magretti and P. beckeri) in Italian Somaliland. It is quite likely that these flies play a much greater part in the spread of such diseases than is imagined at the present time.

[The Tabanidæ are divided into two groups or subfamilies: (1) The Pangoninæ, and (2) the Tabaninæ; the former have spurs on the hind tibiæ and usually ocelli; the latter have neither tibial spurs nor ocelli.

[The Pangoninæ contain two main genera, Pangonia and Chrysops. In the former the proboscis is much elongated, and the third antennal segment is composed of eight rings, and is never angulated or ungulated at the base. The proboscis is often very long.

[In Chrysops, the so-called blinding storm flies, all the three segments of the antennæ are long, the third having only five annulations, and the proboscis short but very strong.

[There are many genera in the Tabaninæ, which are found in all parts of the world, of which two only are shown here--viz., Tabanus and Hæmatopota. The former has the first two segments of the antennæ short, the third angulated at the base, sometimes spurred and composed of five annulations; the second has the second segment short, and the third composed of four annulations--never angulated nor spurred at the base--and the wings are adorned with grey or brown markings. These latter are usually called “brimps” and “clegs” in Britain, the former gad or horse flies, the seruts and mangrove flies of tropical countries.

Family. *Asilidæ* (Wolf Flies).

[These flies are of little importance in regard to the subject dealt with in this book; but I have notes sent concerning the biting habits of one or more species belonging to this family from the Malay States and Africa.

[Asilidæ, or wolf flies, are easily told by the following characters: Large or moderate-sized flies, thickly hairy; head separated from thorax by a narrow neck; eyes separated in both sexes; proboscis firm and horny, adapted for piercing; abdomen long, pointed, and composed of eight segments. Legs strong and bristly, of moderate length. Wings sometimes mottled, lying parallel over the abdomen when at rest. There are nearly 3,000 species. They live mostly upon insects, but some are said to bite animals and man. They are, however, of little importance in this respect.

Family. *Leptidæ.*

[This widely distributed family of flies has a few species which suck the blood of man, and the writer has been personally badly bitten in Norway by a Leptis which was apparently Leptis scolopacea.

[The Leptidæ have usually blotched wings and similar venation to Tabanus; they are elongated flies of moderate or large size, and of dull colours. The antennæ are varied and consist of three segments, either with or without a terminal bristle or with the third segment compound, and in a few they may be almost nematocerous. The wing veins are distinct, very crowded anteriorly, the third long vein is furcate, basal cells large, and there are usually five posterior cells, the anal cell being open in some; the squamæ are always small, sometimes only rudimentary.

[Four are known to be blood-suckers, namely the American Symphoromyia, Trichopalpus obscurus in Chili, and Leptis strigosa and L. scolopacea in Europe. The genus Symphoromyia has a single spur on the hind tibiæ, none on the fore or mid tibiæ, the third segment of the three-ringed antennæ kidney-shaped, and a short proboscis. In the genus Leptis the hind tibiæ have two spurs, and the third antennal segment is not reniform.

[The other biting genus Trichopalpus can be told at once by the elongated proboscis. Most of this family live upon other insects. The larvæ live in earth, decaying wood, sand, stagnant waters, and the nests of wood-boring beetles; they are usually cylindrical and may have fleshy abdominal legs; the anal segment has a transverse cleft, and often two posteriorly directed processes and two stigmata between them. They are all predaceous, and in one genus (Vermileo) make pitfalls in sand like the ant lions (Myrmeleon).

Blood-sucking Muscidæ.

[The blood-sucking Muscidæ are mainly contained in the following genera: Glossina, Stomoxys, Hæmatobia, Lyperosia, Stygeromyia, Philæmatomyia and Bdellolarynx.

[The first is the most important genus on account of the part it plays in the spread of trypanosome diseases. Stomoxys may also serve as a disease carrier. The remainder and a few more genera cause considerable annoyance by their bites, and may also act as occasional carriers of pathogenic organisms. All these flies have their mouth parts elongated to some extent, forming a distinct proboscis, which becomes more or less strongly chitinized; the labella are usually serrated or spiny, and thus form a structure easily capable of piercing the skin. Unlike the Culicidæ, the blood-sucking Muscidæ have the sanguinary habit common to both sexes.

Genus. *Glossina*, Westwood.

[This genus contains sixteen species,[423] all of which are confined to the Ethiopian region. Glossina may be distinguished from other allied genera by the proboscis, the antennæ, wings, and male genitalia. The proboscis projects forwards and has a swollen bulb-like base to the slender labium which holds the two structures, the needle-like epipharynx and the thread-like hypopharynx; the whole proboscis is ensheathed in the maxillary palpi. The antennæ have the first two segments small, the third large with a marked pore, the orifice of the sense organ near the base; from the base of the third segment also arises the three-jointed arista, the first two segments being, however, minute; the third bears a series of from seventeen to twenty-one fine branched hairs on one side. The male genitalia or hypopygium is more or less oval and tumid, its long axis lying in the antero-posterior direction, with a vulviform median groove (the anus) running from the anterior margin to beyond the middle.

[423] This does not include G. maculata, Newstead, which is regarded by Austen as a synonym of G. palpalis, Rob. Des.; according to this authority the curiously spotted appearance of the type and only example of G. maculata is due to foreign matter.

[Newstead has shown the importance of the study of the genitalia in separating species (vide Bull. Ent. Res., ii, pp. 9–36 and 107–110, and iii, pp. 355–360; and Ann. Trop. Med. and Par., vii, No. 2, pp. 331–334).

[The tsetse-flies reproduce differently from all other Muscidæ. The female produces at each birth a single full-grown larva, which is retained within the oviduct and there nourished by the secretion of special glands, and on being born crawls to some hiding place and at once becomes a puparium.

[The larva is a yellowish footless maggot nearly as large as the mother’s body, the skin shagreened and the anal extremity having a pair of large, black, granular prominences separated by a depression containing the breathing pores.

[The puparium is brown of various shades, the tumid lips of the larva being conspicuous, the size and shape of the lips enabling the puparia to be identified.

[These puparia are often found in masses at the base of trees, in hollows in trees and rocks just buried under vegetal debris. These insects are generally confined to definite tracts known as “fly-belts.” They usually occur in damp, hot places on the borders of rivers and lakes, and never far from water in the case of the palpalis group, although others of the morsitans group may be found a considerable distance from water. They are usually absent on grass plains, but may now and then occur there (Kinghorn, vide Hindles’ “Flies and Disease, Blood-sucking Flies,” 1914, p. 274); cover of trees, shrubs, or thick reeds is essential to them.

[Their range in Africa extends roughly from 18° N. to 31° S.

[Glossina palpalis is the chief carrier of the more prevalent type of sleeping sickness. Two distinct types of parasites can produce this disease, viz., Trypanosoma gambiense, which produces the ordinary sleeping sickness, transmitted by G. palpalis, and Trypanosoma rhodesiense the Rhodesian or Nyasaland sleeping sickness, transmitted by G. morsitans, and possibly identical with T. brucei, the parasite of N’agana. Koch has also shown that G. pallidipes, Austen, and G. fusca, Walker, can be artificially infected with the human trypanosome. It appears probable that Koch used G. brevipalpis, not G. fusca, in his transmission experiments, as at that time fusca included nearly all the large tsetses, but brevipalpis is its Eastern representative.

[A TABLE OF SPECIES (modified after Austen) is appended here:--

I.

Glossina palpalis GROUP.

1. Dorsum of abdomen ochraceous buff or buff; third and following segments exhibiting sharply defined, dark brown or clove brown, interrupted transverse bands tachinoides, Westwood. Dorsum of abdomen not so marked 2.

2. Third joint of antennæ pale (cream buff to ochraceous buff), clothed with long and fine hair, forming a conspicuous fringe on front and hind margins pallicera, Bigot. Third joint of antennæ entirely dark (mouse-grey) except at extreme base on outer side, and without a conspicuous fringe of long and fine hair 3.

3. Dorsal surface of abdomen dark sepia brown; median paler area on second segment broad, and more or less quadrate or irregular in outline; hypopygium of ♂ buff or ochraceous buff caliginea, Austen. Dorsal surface of abdomen blackish-brown; median paler area cuneate (i.e., triangular in outline); hypopygium of ♂ grey palpalis, Rob. Desv.

II.

Glossina morsitans GROUP.

1. Hind tarsi entirely dark; small slender species; abdomen bright ochreous or reddish ochreous with dark lateral markings austenii, Newstead. Hind tarsi not entirely dark; abdomen drab- grey, buff or ochreous buff with conspicu- ous dark interrupted transverse bands 2.

2. Last two joints of front and middle tarsi with sharply defined clove brown or black tips 3. Last two joints of front and middle tarsi without sharply defined clove brown or black tips (front and middle tarsi either entirely pale or, at most, two joints of front tarsi faintly brownish at the tips), and last joint and distal half of penultimate joint of middle tarsi light brown, never so dark as to form a sharp contrast with the remaining joints pallidipes, Austen.

3. Third joint of antennæ with a distinct fringe of fine hair on front margin; dark brown or clove-brown bands on abdominal segments extending close to hind margins (i.e., pale ground colour, apart from the median interspace, confined to a very narrow hind border) longipalpis, Wiedeman. Third joint of antennæ without a distinct fringe of fine hair on front margin; dark brown or clove-brown bands on abdominal segments not extending close to hind margins morsitans, Westwood.

III.

Glossina fusca GROUP.

1. Third joint of antennæ fringed with fine hair on anterior and posterior margins; fringe on anterior margin conspicuous under a hand lens magnifying 15 diameters (nominal) when head is viewed in profile 2. Third joint of antennæ with fringe of fine hair on anterior margin so short as to be scarcely noticeable under a hand lens magni- fying 15 diameters (nominal) when head is viewed in profile (longest hairs in fringe in length not exceeding one-sixth of width of third joint); palpi long and slender 3.

2. Longest hairs in fringe on front margin of third joint of antennæ, in length equal to from one-fourth to one-third (not exceeding one-third) of width of third joint; palpi of moderate length tabaniformis, Westwood. Longest hairs in fringe on front margin of third joint of antennæ in length equal to from one-half to three-fourths of width of third joint; palpi noticeably long and slender nigrofusca, Newstead.

3. Pleuræ drab-grey or isabella-coloured, hind coxæ buff or greyish-buff fusca, Walker. Pleuræ dark grey; hind coxæ mouse-grey fuscipleuris, Austen.

IV.

Glossina brevipalpis GROUP.

1. Dorsum of thorax with four sharply defined brown, more or less oval or elongate spots, arranged in a parallelogram, two in front and two behind the transverse suture; proboscis bulb with a sharply defined brown or dark brown tip longipennis, Corti. Dorsum of thorax without such spots; proboscis bulb not brown or dark brown at tip 2. Wings with upper thickened portion of anterior transverse vein much darker in colour than adjacent veins and thus standing out con- spicuously against the rest of the wing brevipalpis, Newstead. Wings with upper, thickened portion of anterior transverse vein not much darker in colour than adjacent veins, and thus not standing out conspicuously against the rest of the wings (wings practically unicolorous) medicorum, Austen.[424]

[424] Newstead has recently described another species as G. severini (Ann. Trop. Med. and Par., 1913, vii, No. 2, pp. 331–334). It is allied to G. fuscipleuris, Austen.

*Glossina palpalis*, Rob. Desv.

[This is the chief carrier of sleeping sickness in Nature. It is found in places over the whole of West Africa from the mouth of the Senegal River to Angola, and extends eastwards into the Bahr-el-Ghazal. The eastern boundary follows the valley of the Nile and includes the eastern shores of Lakes Victoria and Tanganyika; from the southern end of the lake the boundary tends south-west, approximately following the frontier between North-eastern Rhodesia and the Congo Free State, and passing through the Katanga district of the latter country into Angola (Austen). It may occur up to 3,000 ft.; but, according to Bagshawe, it has not been recorded above 4,000 ft. It feeds on the blood of many animals, including reptiles, amphibia, birds, and even amphibious fishes, as well as all the wild mammals. It seems, however, to possess a decided predilection for man, and undoubtedly thrives better upon mammals and birds than upon cold-blooded animals.

[It is not usually found far from water, requiring a humid atmosphere and temperature of about 85° F. (shade). But a marked seasonal distribution is shown, the flies considerably extending their range during the rainy season, and thus visiting districts which are dry for the greater part of the year; as the rains diminish the fly gradually leaves the temporary haunts and returns to the more permanent ones. It bites only by day, and then only in sunny weather, and usually lives in shade.

[Roubaud has shown that the first larva produced is about three weeks after copulation, and that others are produced at an interval of nine or ten days. The puparium stage is rapidly produced after the expulsion of the larva, often in three-quarters of an hour. The puparium stage lasts from thirty-two to thirty-five days. The puparia occur in well-drained humus close to water, sheltered by trees or bushes, in crevices in rocks, and between the exposed roots of trees, sometimes in sand.

[Bruce has shown that only a very small percentage of flies fed experimentally on infected animals ultimately become infective, and that the infectivity of this small percentage depends upon a delayed infection of the salivary glands.

[A variety, wellmani of Austen, is found in Angola, Gambia, the Katanga district of the Congo Free State, the Matondwi Islands of Tanganyika, etc.

*Glossina morsitans*, Westwood.

[This species has been shown by Kinghorn and Yorke, and also by Bruce, to be responsible for the transmission of Trypanosoma rhodesiense, the micro-organism producing sleeping sickness in man in Rhodesia and Nyasaland and also in parts of German and Portuguese East Africa. Fisher and Taute have demonstrated experimentally that Trypanosoma gambiense--the sleeping sickness parasite of other parts of Africa--may also be transmitted by this fly, and in addition it is known to be capable of disseminating several species of trypanosomes pathogenic to animals. Of these, T. brucei (=? T. rhodesiense), the parasite of tsetse disease, first incriminated by Bruce, is perhaps the most important.

[It is the most widely spread of all tsetse-flies; its range extends from Senegambia in the north-west to Southern Kordofan and Southern Abyssinia in the north-east, and then southwards to the Bechuanaland Protectorate, North-eastern Transvaal and Zululand. The actual localities given by Austen are Gambia, French Guinea, Gold Coast, Togoland, Dahomey, Northern Nigeria, Congo Free State, the Bahr-el-Ghazal, the Uganda Protectorate, German East Africa, and Portuguese East Africa.

[This species is confined to “belts,” often of very limited extent, and appears to prefer regions where there is sufficient vegetation for moderate but not excessive cover and a hot, moderately dry climate. It is not nearly so dependent upon water as is G. palpalis, and generally is most active in a dry atmosphere; some observers, however, state that in certain districts it is more common along the banks and edges of rivers. This tsetse-fly has been taken as high as 5,500 ft. altitude. It infests native villages as well as the bush. Like other tsetse-flies it bites not only during the hottest part of the day, but also on bright warm moonlight nights, and it feeds on the blood of all mammals.

[The structure of the male genitalia of those representatives of G. morsitans occurring on the West Coast of Africa and in parts of the Soudan presents certain constant differences from that of the typical form of this species; this form is known as G. morsitans, race submorsitans, Newst.

Genus. *Stomoxys*, Geoffroy.

[The members of this genus which occur in temperate and tropical countries are provided with a hard, slender, shiny black proboscis which projects horizontally from beneath the head; by means of this structure they can bite severely. In general appearance they resemble house flies, but the proboscis at once distinguishes them. In many parts of Britain they are known as storm flies on account of their frequent appearance indoors previous to a storm of rain or wind, which I have invariably found to be correct; they are also called stinging flies. In colour they are greyish, dusky or brownish-grey or black, varying from 5 to 7 mm. in length; the thorax has dark longitudinal stripes and the abdomen dark spots or bands. In the male the eyes are closer together than in the female. These flies usually occur in stables and farmyards, along woods and in lanes, and mainly attack mammals.

[One species (Stomoxys calcitrans, Linnæus) occurs practically all over the world. The female lays her eggs in moist, warm, decaying vegetation; as many as eighty may be laid by a single female. The ova are white, banana-shaped, with a broad groove on the shorter curvature; they may hatch in two or three days. The creamy-white larva tapers to a point at the head end, and is truncated at the tail end. Two black mouth hooks are plainly visible at the cephalic extremity. There are two plates on the posterior surface of the last segment which bear the respiratory pores, nearly circular in outline. It reaches maturity in fourteen to twenty-one days; when mature it is 11 mm. long. The pupal stage is passed in the old larva skin and lasts from nine to thirteen days; it is barrel-shaped, 5 to 8 mm. long, and of a bright reddish-brown to dark chestnut-brown colour.

[This insect may act as a carrier of anthrax, and has been proved to be the agent of an extensive epidemic of malignant pustule in the Isle of Pines, New Caledonia.[425]

[425] Bull. des Séances de la Soc. ent. de France, 1878, pp. cxliv, cxlv.

[Noè’s[426] experiments tend to show that it is an intermediate host and transmitter of Filaria labiato-papillosa of the ox.

[426] Atti della Reale Accad. dei Lincei, Anno CCC. Se Quinta, 1903, xii, 2 sem. fasc., pp. 387–393.

[Surra is generally stated to be transmitted by Stomoxys as well as Tabanus, and yet Nitzman in the Philippines obtained uniformly negative results in exhaustive experiments. Others have also been unsuccessful. Certainly Stomoxys can transmit the disease in French West Africa (Bonet and Roubaud), and mechanically has been proved to be capable of disseminating other trypanosomes (experimentally): sleeping sickness (T. gambiense); nagana (T. brucei); souma (T. cazalboui); and el debat (T. soudanense).

[S. calcitrans may also be a carrier of poliomyelitis (Rosenau and Brues, Harvard Alumni Bulletin, 1912, xv, No. 9, pp. 140–142). Several species are now known (S. brunnipes, Grünb.; S. inornata, Grünb.; S. nigra, Macq.; S. omega, Newst.; S. ochrosoma, Speiser, etc.).

Genus. *Lyperosia*, Rondani.

[A genus of small flies which bite man and animals, but are not so far connected with the transmission of any disease in man, but in Java it appears to carry surra (P. Schat, Meeledeel Praefstation Oost-Java, 1903, 3e ser., No. 44), the species being Lyperosia exigua, Meijere. These flies can be told from Stomoxys by the palpi being broader, flattened laterally, and as long, or nearly so, as the proboscis. When not feeding the palpi enclose the proboscis, as in Glossina. They are usually about half the size of Stomoxys, and are the smallest blood-sucking Muscidæ. They frequently swarm around and upon domesticated animals.

[The life-history of the horn fly in America (L. irritans, Linn.) is well known. It lays its ova singly in freshly dropped cow-dung, and there the maggots feed, pupating in the soil beneath.

[Patton and Cragg also give some details as to the life-history of Liperosia exigua (“Medical Entomology,” p. 375) as follows: “L. exigua, whose habits have been observed in Madras, usually lays twelve eggs at a time. The flies immediately return to the cow and the process is repeated when the dung is again dropped. The larvæ migrate from the dung when about to pupate, and the puparia are always found in the earth at some distance away or under the sides of the patch of dung. The fly usually hatches out in five days, though sometimes as late as the eighth. Weiss has studied the life-history of irritans var. weisii from Algeria; its larval stage lasts five days, and the flies hatch out of the puparia in another five days.”

[The other biting genera of Muscidæ, Hæmatobia, Hæmatobosca, Bdellolarynx, Stygeromyia, and Philæmatomyia, although sometimes annoying to man, have not in any way been connected with any disease.

[The horse fly (Hæmatobia irritans, L.[427]) attacks cattle chiefly, but now and then man is bitten. The different species can be told from Stomoxys by the palpi being nearly as long as the proboscis.

[427] This is apparently the stimulans of Meigen.

[The genus *Philæmatomyia*, Austen, is intermediate between Stomoxys and Musca in structure, and between the non-blood-sucking Musca, as M. domestica, and the blood-sucking Musca pattoni, Austen, which feeds on the blood exuding from the bites of true blood-suckers. They occur in Central Africa and India, Ceylon and Cyprus (vide “The Life-history of Philæmatomyia insignis, Austen,” Ann. Trop. Med. and Par., 1912, v, p. 515).

[Two flies belonging to the family *Anthomyidæ* also attack man, namely:--

[Hydrotæa meteorica, L. (the meteoric fly). This fly attacks man as well as animals. They especially bite around the eyes and nostrils of animals, but are not so particular with man; the head, however, is usually chosen. Linnæus called it the meteoric fly because it often forms clouds around horses’ heads at the approach of rain. The Hydrotæas are usually black or blue-black in colour with bare eyes and simple abdomen, the front femora peculiarly constructed. H. meteorica, L., occurs in Britain.

[The members of the genus Hydrophoria, Desvoidy, also bite man.

*Pupipara* or *Eproboscidæ*.

[The Pupipara are all blood-suckers, the majority occurring as parasites on mammals and birds, where they are more or less permanent parasites. Occasionally some may attack man. They all produce their young fully formed, and they assume the pupal stage immediately after extrusion. The puparia are large. They are mostly flat, louse-like flies which may or may not be winged. In the case of Melophagus I have found the puparia are often passed by the female. The winged forms have a short quick flight, and when disturbed will seek shelter in man’s hair or beard. Two main families occur: (1) the Hippoboscidæ, and (2) the Nycteribiidæ. The former occur on animals and birds, the latter on bats only, but may invade man. Two other families are known--the Braulidæ (bee parasites) and the Streblidæ (bat parasites).

[The mouth of the Hippoboscidæ is long and sharp, forming a proboscis. The thorax and abdomen are flat and leathery. The legs are stout and strong, and terminate in large dentate claws and other structures of use in holding on to the hair or feathers of their host when blood-sucking.

[Austen says it is probable that the Hippoboscidæ are descended from ancestors belonging to the Muscidæ, which underwent modification in bodily structure as the consequence of the adoption of a parasitic mode of life.

[Two wings are present in the true Hippoboscæ, Hippobosca equina (of the horse), H. camelina (of the camel), H. maculata (of oxen), and H. capensis (of dogs), but are absent in Melophagus, the sheep tick or ked fly (M. ovinus).

[In two genera, Lipoptena and Echestypus, wings are at first present, but are lost as soon as the fly finds its permanent host.

[With regard to their biting man, such is only occasional. I have known sheep shearers to be badly bitten by Melophagus ovinus, and have more than once been attacked myself when standing where shearing is taking place. Sharp records the grouse parasite, Ornithomyia lagopodis, as once biting severely a gamekeeper in Scotland. There are also records of H. maculata biting man in Africa and India.

[Although so far not connected with any human disease, it is interesting to note Theiler has shown that Hippobosca rufipes, v. Olfers, and H. maculata, Leach, are capable of transmitting Trypanosoma theileri, Laveran, the cause of gall sickness amongst cattle in the Transvaal. It is now considered, however, that Trypanosoma theileri is non-pathogenic, and that the cause of gall sickness is a piroplasma-like organism known as Anaplasma marginale. Theiler, Laveran and Mesnil all hold this view (vide Laveran and Mesnil, “Trypanosomes and Trypanosomiases,” second edition, 1912, p. 330).

[Lynchia.--Three members of this genus have been shown to transmit the non-pathogenic (?) organism, Hæmoproteus columbæ amongst pigeons in Algeria and S. America.

Insects and Epidemic Poliomyelitis.

[In a recent number of the Journal of Economic Entomology,[428] Brues and Sheppard point out the possibility of acute epidemic poliomyelitis (infantile paralysis) being an insect-borne disease. They summarize as follows:--

[428] Charles T. Brues and Philip A. E. Sheppard, “The Possible Etiological Relation of certain Biting Insects to the Spread of Infantile Paralysis,” Journ. Econ. Ent., 1912, cciv, pp. 305–324.

[Many facts connected with the distribution of cases and the spread of epidemics of this disease with histories of insects bites, suggest at least that the disease may be insect-borne. Field work during the past summer, together with a consideration of the epidemiology of the disease so far known, points strongly towards biting flies as possible carriers of the virus. It seems probable that the common stable fly (Stomoxys calcitrans, L.) may be responsible to a certain extent for the spread of acute epidemic poliomyelitis, possibly aided by other biting flies such as Tabanus lineola. No facts which disprove such a hypothesis have as yet been adduced, and experiments based upon it are now in progress.

[If the disease should prove to be common to any species of domestic animals, as is now strongly suspected, a secondary connection of ticks in spreading the disease among such animals seems probable, as has been mentioned.

[The following is some of the more important literature on Diptera in general: Meigen, J. W., “Syst. Besch. d. bek. europ. zweiflügligen insecten,” 1818–1838, 7 vols.; Brauer, F., “Monographie der Oestriden,” Wien, 1863; Idem, “Nachtr. hiersu,” Wien. ent. Zeit., 1887, vi, pp. 4, 71; Schiner, J. R., “Fauna austriaca: die Fliegen,” Wien, 1860–64; Löw, Fr., “Ueber Myiasis und ihre Erzeuger,” Wien. med. Wochenschr., 1882, xxii, p. 247; 1883, xxxiii, p. 972; Joseph, G., “Ueb. Fliegen als Schädlinge und Parasiten des Menschen,” Deutsch. med. Zeit., 1885, i, p. 37; 1887, iii, pp. 713 and 725; Peiper, E., “Fliegenlarven als gelegentl. Paras. d. Mensch.,” Berlin, 1900; Theobald, F. V., “Monograph of the Culicidæ of the World,” 1901–1911, 5 vols. and 1 atlas, plates; Austen, E., “A Monograph of Glossina Tsetse-flies,” 1903, 1 vol.; Van der Wulp, “Diptera neerlandica,” 1877; Walker, “Insecta Britannica: Diptera,” 1851–53 and 1856; Lundbeck, “Diptera danica,” 1907–12; Zetterstedt, “Diptera scandinaviæ,” 1850; Theobald, “British Flies,” 1892; Aldrich, “N. American Diptera,” 1905; Loew and Osten Sacken, “Monographs of the N. American Diptera,” 1862–63 and 1869; Macquart, “Diptera exotique,” 1830–47; Rondani, “Diptera exotica et Italica,” 1863–68; Williston, “Manual of Families and Genera of N. American Diptera,” second edition; Verrall, “British Flies.” A fuller literature will be found in Peiper, as well as in Huber’s “Bibliographie d. klin. Ent.,” 1899, iii, Jena, in the Bibliography at the end of this work and in the Rev. of App. Ent. (Dulau and Co., London), where all references to modern research can be found.--F. V. T.]

ADDENDA.

*Akamushi or Kedani Sickness* (vide also p. 487).--Schuffner (Far East. Assoc. Trop. Med., Compt. rend. Trois. Cong. Biennial, 1913, Saigon, 1914, pp. 309–315) states he observed a peculiar fever in Deli, Sumatra, somewhat resembling typhoid. This he traced either to a mite or tick. He figures the possible carriers, namely, a Trombidium and Cheyletidæ. He calls this disease pseudo-typhus--a variant of Japanese kedani sickness, which, he says, also occurs in the Philippines.

*Ticks.*--AFRICAN TICK FEVER: Marzinovsky (Proc. of Conference of Bacteriologists and Representatives of Medical Sanitary Authorities on the Campaign against Infectious Diseases in connection with the War, Soc. Russ. Physicians in mem. Pirosov, Moscow, 1915, pp. 56–68), states that African tick fever has been imported into Persia, and that it is there carried by Ornithodorus tholosani.

TICK PARALYSIS: Todd (“Paralysis and Tick-bite,” Can. Med. Assoc. Journ., 1914, iv, No. 9, pp. 825–826) refers to paralysis ascribed to the bites of ticks in children, and possibly adults, in America, British Columbia and Australia. He states that a young child, perfectly well one day, has more or less complete paresis or paralysis on the next, fever, a rapid pulse, and other constitutional symptoms. The child may be dull and stupid, and may have convulsions. If the tick is not found and removed the child may die, but if it is removed, the symptoms disappear and recovery is complete in a few hours. The tick must be entirely removed.

*Diptera.*--PSYCHODIDÆ: Bolt (China Med. Journ., Shanghai, xxix, No. 2, pp. 78–86) states that sand-flies (Plebotomus) and the fever due to them are common in North China, May and June being the worst months. The natives of the region appear to be immune, but all others suffer. Old ruined buildings are the favourite haunts of the Phlebotomus. The species of Phlebotomus has not been determined.

*Pulicidæ.*--DERMATOPHILUS (SARCOPSYLLA) PENETRANS, OR THE “JIGGER.”--This flea (vide p. 544) is believed by Lama (Giorn. Ital. Mal. Ven., Milan, 1914, xlix, pp. 465–472) frequently to carry leprosy and he points out that the early lesions of leprosy usually appear on the uncovered parts of the body. This flea also attacks rats.

*Brachycera.*--LEPTIDÆ (vide p. 603): White, A. (“The Diptera-Brachycera of Tasmania,” part I, Papers and Proc. Roy. Soc. of Tasmania for 1914, 1915, pp. 35–74), describes a new blood-sucking Leptid, Spaniopsis tabaniformis, which resembles a small gad fly (Tabanus) in appearance.

Pycnosoma putorium: This is believed by Roubaud (“Les Producteurs de Myiases et Agents similaires chez l’homme et les animaux,” Paris, 1914, part I) to be largely concerned in the spread of amœbic dysentery in French West Africa.

Lucilia argyrocephala, Macquart: This green-bottle fly is described by Roubaud as producing myiasis in Africa (“Les Producteurs de Myiases et Agents similaires chez l’homme et les animaux,” 1914, Paris, part I). It attacks ulcers and sores in man and animals.

Auchmeromyia luteola, Fabr.: Schwetz (Ann. Trop. Med. and Par., 1914, viii, No. 3, pp. 497–507), collected a large quantity of this insect at Kabinda. He placed them in flasks with sand and a few days later they pupated, and in fifteen days several flies hatched out. The larval period varies from an unknown minimum up to several months. The larva may live for at least two months without food. A female oviposited on the 17th, and on the 18th one larva hatched. The pupal stage seems to last eight to fifteen days. The larvæ appear to bite by day as well as night according to native information.

Cordylobia anthropophaga, Grünb.: Roubaud (“Etudes sur la Faune parasitaire de l’Afrique occidentale française,” part I, “Les Producteurs des Myiases et Agents similaires chez l’homme et les animaux,” Paris, 1914) gives the life-history of this species. One fly laid 150 ova in a glass vessel, on the sides, and on some rotten fruit, and died the following day. He found that fifteen larvæ just hatched placed on sand in a glass vessel with a guinea-pig gave rise to characteristic tumours on the ventral surface of the body and the anus. Other experiments failed. It thus seems that infection takes place from larvæ which have hatched apart from the host. Infection of man is regarded as accidental; no positive infection of horses, oxen, sheep or pigs is known--it is rare in goats, and poultry never seem to be attacked. The result of experiments tends to show that the apparent choice of a host is mainly a question of body temperature. The larva, whether freshly emerged or eight to ten days old, penetrates the skin immediately, boring obliquely between the epidermis and dermis. Once removed from the tumour the maggot cannot bore again. The first moult takes place about three days after penetration, and the total period of residence in the host is seven to eight days. Upon emerging the larva falls to the ground and buries itself. In two or three days it pupates and this stage lasts no longer than twenty days. High temperatures, such as 95° F., appear to be fatal.

*Myiasis.*--Coates, G. M., “A Case of Myiasis Aurium accompanying the Radical Mastoid Operation,” Journ. Amer. Med. Assoc., Chicago, Ill., 1914, lxiii, pp. 479–480: Apparently C. macellaria, forty to fifty coming away with the gauze after the operation.

Huber, G. U., and Flack, F. L., “An Unusual Case of Screw-worms in the Nose and Nasal Accessory Sinuses,” Journ. Amer. Med. Assoc., Chicago, 1914, lxiii, pp. 2288–2289.

*Auricular Myiasis.*--Francaviglia, M. C., “An cora sulla myiasi auricolare,” Boll. Sedute Accad. Gioenia, Catania, 1914, No. 31, pp. 15–23. This writer mentions the following parasites in the human ear: Sarcophaga carnaría, L.; Wohlfartia magnifica, Schiner; Chrysomyia macellaria, F.; Calliphora vomitoria, L.; and Anthomyia pluvialis, L. He refers to a severe myiasis in Russia, due to a fly variously recorded as Sarcophaga wohlfarti, Rond.; S. ruralis, Meig.; or Sarcophila meigeni, Portsch. These are all probably synonyms of W. magnifica. Chrysomyia macellaria, in Central America and South America, is quite as harmful as S. carnaria, causing perforation of the tympanum and meningitis. Lucilia nobilis and L. cæsar have also been incriminated. Of the sub-family Anthomyinæ, the larvæ of Fannia scalaris, Meig., F. canicularis, Meig., F. incisurata, Zett, and Hydrotæa meteorica, L., are chiefly associated with myiasis. He recommends, if the larvæ are outside the tympanum, an injection of chloroform vapour by a few drops of water saturated with chloroform, by an emulsion of 5 per cent. carbon bisulphide or with benzine. When detached they may be removed with forceps or a solution of boric acid. If the tympanum has been perforated, the larvæ must be removed at once.

Francaviglia also records the larva of Oestrus ovis in the human ear (Boll. Sedute Accad. Gioenia, Catania, 1914, No. 31, pp. 23–27).

*Body, Head, and Clothes Lice.*--Lobaczewski (Wien. klin. Wochenschr., Vienna, 1915, xxviii, pp. 373–374) recommends the impregnation of body linen with a 30 per cent. solution of oleum betæ in 96 per cent. alcohol as an efficient method of keeping the body free of lice. But the process must be renewed each time the linen is washed and it takes fifteen minutes to carry out. On adding the oil to the alcohol, a portion of the former is precipitated, the supernatant fluid is decanted and poured over the linen, which is wrung out in it and dried. The garments retain their lice-proof properties until washed. Three days after wearing the clothes thus treated no lice remain on the body.

Portnikov, Proc. of Conference of Bacteriologists and Representatives of Medical Sanitary Authorities on the Campaign against Infectious Diseases in connection with the War, Soc. Russ. Physicians in mem. Pirosov, Moscow, 1915, p. 131.

Pediculus capitis and Phthirus pubis are shown to be successfully controlled by applying spirit extract of sabadilla and both white and grey mercury ointment, solution of corrosive sublimate of a strength of 1 in 250 to 1 in 100, amyl and ethyl alcohol, benzine, chloroform, carbon tetrachloride, methane, birch tar, liquid of malinin, etc. The control of Pediculus vestimenti by the mixture of tartaric acid and sodium sulphite slightly moistened with water is advised. It is placed in small linen bags underneath the shirt; the heat of the body produces a reaction which continues for two days, giving off a large amount of SO_{2}, which spreads beneath the shirt and kills all the parasites but does not affect the skin. Marzinovsky, in the same Proceedings (pp. 56–68), gives a number of remedies for Pediculus vestimenti (called humanus), and mentions quinine or mercury, which latter the natives in Turkestan carry on their hands and legs in bracelets soaked in mercury compounds. He also mentions ethereal oils, the most effective being clove oil, eucalyptus, oil of anise and camphor. He recommends for disinfecting clothing for army purposes the chamber used by the Japanese on a large scale. Kummerfelds’ wash is advised, and is prepared as follows: 20 parts of precipitated sulphur are incorporated in a mortar with 50 parts of glycerine; 2 parts of camphor are separately ground with 50 of eau-de-Cologne and 20 of borax, and 870 parts of distilled water are added; the whole is mixed together and 3 drops of an extract of musk are added; shake in order to prevent the sulphur settling down; 50 parts of ether are added to the mixture. This sounds an expensive and troublesome preparation to make.

Shipley A. E., “Flowers of Sulphur and Lice,” Brit. Med. Journ., 1915, p. 295. It is here stated by Dr. Lounsbury that the South African troops were supplied by the Government with bags of flowers of sulphur sewn in small calico bags and secured to the underclothing next the skin as a preventive of lice. The bags were 2 in. square, one on the trunk and one against each leg. This is a generally accepted preventive, but is best mixed with equal parts of creosote and naphthalene.

Shipley, A. E., “Insects and War,” Brit. Med. Journ., September 19 to November 14, 1914. General advice given re lice.

SUPPLEMENT:

CLINICAL AND THERAPEUTICAL NOTES.

PROTOZOA.

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