An elementary treatise on midwifery, or, Principles of tokology and embryology

Front matter

PUBLISHED BY

GRIGG ife ELLIOT,

J\y>. 9 J%*orth Fourth Street^

Author's Preface

Confounded with the other branches of medicine, and pursued almost exchisively by mere medicasters during a long series of ages, the Art of Midwifery has advanced with extreme slowness. Among the Egyptians, the Hebrews, the Greeks, and the Romans, it was reduced in some sort to what concerns the cutting of the umbilical cord; and even at the present time, in countries that are imperfectly civilised, those who make a profession of it inspire so little confidence, that the husband is still compelled to imitate the conduct of the first man, that is to say, he becomes the accoucheur of his wife. These primitive notions have doubtless long ceased to exist amongst us; in our day the Art of Midwifery is especially seen to acquire a rapid movement, and to progress equally with the other departments of the art of curing. It would, however, be wrong to conclude from hence, that every thing has been already done, and that no further improvements can be made. The Science of Obstetrics ought to follow the movements of the age, and advance if it would not retreat. It seems to me that it may be defined, the ensemble of knowledge relative to the reproduction of the human species. By studying it under this extensive and philosophic view, and by doing away

X PREFACE.

the absurd and vulgar prejudice, that it is impossible to be at the same time a skilful accoucheur and an able physician, we shall succeed in establishing it upon a basis worthy of the subject!

In this book I have endeavored not to be unjust to any one. I have spoken on all occasions without being influenced by hatred or prejudice, and I may add, without enthusiasm, and with absolute independence. The sciences compose a republic in which every man is at liberty to make researches, to examine and think for himself, as well as to say what he thinks. Truth is the avowed object of all who cultivate them: it may be reached by a hundred different routes, and I could never understand how any reasonable man could be offended because his ideas fail to be received as laws for other men.

In adopting a course somewhat different from that pursued by the modern classic writers, I was not misled as to its merits. No person attaches less importance to classifications than I do, or is more fully convinced that every one has an equal right to choose for himself. The course I have chosen appeared to me to be more natural than any other; I found that one was necessary for my purposes, and I preferred this one; I shall, therefore, make no further attempt to justify it. It belongs to the public to decide whether it be good or bad.

I have given a name to the science of the accoucheur; in the first place, because it is a substitute for a periphrasis; and in the next, because it is quite extraordinary that that science should have remained until the present day without any special qualification in France. From the earliest years of my studies, I employed the term {obstetricie) obstetrics, derived from the Latin obstetrix, midwife. I think it more uniform in acceptation than the word obstetrique, which is used in Germany, and which M. Dug^s has desired to establish among us. But the word tokology, derived from toxoi, child-birth, and from ^oyoy, word, out of which may be constructed the

PREFACE. xi

terms tokological, tokologist, tokologue, tokograph, Sic, and which present nothing hard or difficult in their pronunciation, has seemed to me more conformable to the habits of our language and the rules of grammar.

It is of the nature of a preface to set forth the motives of the author of a doctrinal book, and the advantages which he supposes himself to enjoy over his predecessors. I hope that I may be permitted to dispense with this common form. Since the time of Baudelocque very good treatises on Midwifery have been composed; I am the first to proclaim it, and have not the smallest intention to contest the rights which their authors may have acquired to the enjoyment of the public esteem. But at the present day, every thing proceeds with such rapidity, that each moment is, so to speak, marked by new wants. Besides, as the last speaker, I might hope that I could produce a work, if not better, at least equally useful with others; it remains to be seen whether I have succeeded.

In composing it, I have attempted to make a profitable use, not only of the works of my own countrymen, whether ancients or contemporaries, but also of all such foreign writers as I could have access to. Numerous materials have also been furnished by between one thousand and twelve hundred labors, examined with care either at the Maternite at Tours, and the hospital Saint Louis, while I was a student there, or at the hospital de Perfectionnement, while I was in service there as chef de Clinique, or at my amphitheatre and in my private practice, since I began to teach tokology; lastly, I have thought it best to embody in the work a detailed extract of a treatise on Embryology, which I have been preparing for a long time past.

I may be permitted to make an appeal to my brethren upon this subject. If, in the space of six years, I have been enabled to make dissections of nearly one hundred and forty products of conception within the "third month of gestation, I am inxii PREFACE.

debted for those opportunities to the kindness of a great many physicians and female practitioners of midwifery. I shall testify my thankfulness to them in another work, but in the mean time, I cannot express the amount of obligations they will confer by continuing to send me such specimens.

Chapter I

Of the Parts that are concerned in Generation, Pregnancy, and Labor, 17

ARTICLE I.

SECTION 1. Of the Bones of the Pelvis, . . . . . 18

§. L Of the sacrum, ..... 18

§. II. Of the cocc)rx, . . . . . 19

§. III. Of the coxal bones, .... 20

Of the Articulations or Symphysis of the Pelvis, . . 21

Of the Pelvis in General, ..... 23

§. I. External surface, ..... 23

§. II. Internal surface, ..... 23

§. III. Straits of the pelvis, .... 25

§. IV. Dimensions of the excavation, ... 27

§. V. Base of the pelvis, ..... 28

§. VI. Dimensions of the pelvis unconnected with its axes or

§. VII. Differences of the pelvis in respect to ages, sexes, and

§. VIII. Of the recent pelvis, .... 32

§. IX. Uses of the pelvis, .~ .... 33

XIV

CONTENTS.

SECTION 4.

Of the Deformed Pelvis, .... §. I. Deformity from excess of amplitude, §. II. Defonnity from want of amplitude, . §. III. Faulty direction of the axes, §. IV. Causes of deformities of the pelvis, §. V. Of the mensuration of the pelvis,

34 35 35

40 40 42

ARTICLE II.

Of the External Parts of Generation, §. I. Of the mons veneris, §. 11. Of the labia, §. III. Of the lesser labia, §. IV. Of the clitoris, §. V. Of the vestibule, §. VI. Of the urethra, §. VII. Of the hymen, §. VIII. Of the myrtiform or vaginal caruncles, §. IX. Of the perineum, fossa navicularis, fourchette, froenum,

commissure, .....

§. X. Differences betvi^een the external organs of generation in

women and those of brutes, §. XI. Anomaly of the external organs of generation.

Internal Genital Organs, .

§. I. Of the uterus, .

A. External surface, .

E. laternal surface,

C. Dimensions of the womb,

D. Structure, . §. II. Fallopian tubes, §. III. Ovaries, §. IV. Ligaments of the uterus, §. V. Of the Vagina, §. VI. Of the sexual organs in general.

49 49 49 50 51 52 53 53 55

56 57

§. VII. Varieties in the internal organs of generation in animals, 74

CONTENTS.

§. VIII. Difference according to ages, §. IX. Anomalies, . §. X. Hermaphrodism,

XV

75 76 81

CHAPTER II. Functions of the Sexual Organs

ARTICLE I.

Of Menstruation, or the Catamenial Discharge,

ARTICLE II.

Of the Generation or Procreation of Germs, §. I. Of the female germ, . §. II. Of the male germ.

Of Fecundation, .

Of Conception, .

95 95 96

CHAPTER HI.

History of Gestation,

ARTICLE I.

SECTION 1.

Of Uterine Pregnancy, . . . . .

§. I. Local phenomena, . . . .

§. II. Sympathetic phenomena and rational signs.

104 104 116

XVI

CONTENTS.

§. III. Sensible signs, ..... 121

§. IV. Of touching, ..... 121

§. V. Of ballottement, ..... 126

§. VI. Of auscultation, ..... 128

Of Extra-uterine Pregnancy, ..... 133

§. I. Of ovarian pregnancy, .... 133

§. II. Of abdominal pregnancy, .... 134

§. III. Of tubal pregnancy, .... 135

§. IV. Of interstitial pregnancy, . . ... 136

§. V. Causes of extra-uterine pregnancy, . . . 137

§. VI. Signs and terminations of preternatural pregnancy, 138

ARTICLE II.

Of False Pregnancy,

ARTICLE III.

Of Pregnancy as it regards the sex of the Foetus, . . 146

§. I. Is it possible to ascertain the sex of the foetus during

§. II. Is it possible to procreate either sex at pleasure? . 148

§. III. Of the influence of the seasons and of public prosperity upon the production of the sexes and the proportion of conceptions, .... 151

CHAPTER IV. Of the Human Ovum

ARTICLE I.

Of the Appendages of the Foetus,

Of the Membranes, .....

§. I. Of the caduca or comiecting membrane, §. II. Of the proper membranes of the ovum, A. Of the chorion.

153 153 158 158

CONTENTS.

XTU

B. Of the amnios, ni. Of the water of the amnios, .

Of the Vesicles of the Embryo, .

Of the umbilical vesicles,

Of the allantois.

Of the Cord and Placenta,

Of the umbilical cord,

S.II.

Of the placenta.

163 161

167 167 172

176 176 180

Of the Foetus,

ARTICLE II.

SECTION I.

Development of the Embryo and of the Foetus, . §. I. Of the embryo in general, §. II. Of the head and organs of the senses, §. III. Of the members and lower parts of the trunk, §. IV. Of the foetal head at term, §. V. Of the attitude and position of the foetus during pregnancy, ..... §. VI. Of superfcetation, ....

Functions of the Foetus, .

§. I. Of the nourishment of the foetus, §. II. Circulation of the foetus, §. III. Of the respiration of the foetus, §. IV. Of the viability of the foetus,

190 191

193 195 202

207 209

213 213 231

225 227

ARTICLE III.

Of Abnormal Expulsions of the Human Ovum,

SECTION 1.

Of Abortion, .....

Of the terra of Gestation and of Retarded Births,

2*

XVlll

CONTENTS.

Of Precocious or Early Births, .

Chapter V. Article L

Of Labor in General,

SECTION 1.

Of the Causes of Labor, ....

§. L Efficient causes, ....

§. IL Determining or occasional causes,

SECTION 2. Of Labor, .....*

§. I. Precursory or preliminary symptoms of labor, §. II. First stage, or period of dilatation, . §. III. Second stage, or period of expulsion, §. IV. Of labor-pains, §. V. Of the dilatation of the OS uteri, §. VI. Of the discharge of glairy mucus, §. VII. Of the bag of waters,

254 260

265 267 268

272 277 280

ARTICLE II.

Of Eutocia or Simple Labor,

Of Natural Eutocia,

§. I. Presentation of the vertex, First, or occipito-anterior position,

A. First variety.

Left occipito-acetabular poistion,

B. Second variety.

Right occipito-acetabular position.

289 290 292

CONTENTS. xix

C. Third variety.

Occipito-pubic position, . . . . . . 299

Second, or occipito-posterior position, .... 302

A. First variety.

Left fronto-acetabular position, ..... 303

B. Second variety.

Right fronto-acetabular position, ..... 305

C. Third variety.

Fronto-pubic position, ...... 307

§. II. Presentation of the face, .... 310

A. Right mento-iliac position, . . . . 313

B. Left mento-iliac position, .... 313

C. Mento-sacral position, . . . . 314

SECTION 2.

Of Unnatural Eutocia, . . . . . . 315

§. I. Presentation of the feet, . . . .321

First; Calcaneo-anterior position, . . . .321

A. First variety.

Loins in front and towards the left, . . . .321

B. Second variety.

Loins in front and towards the right, .... 323

C. Third variety.

Loins directly in front, ...... 324

Secondly ; Calcaneo-posterior position, ... - 325

Presentation of the knees, ..... 329

Presentation of the breech, . . . • . . 330

Of the Conduct of the Accoucheur during Labor, . . 332

332 336 339 340

§. I. Of the diagnosis, ....

§. II. To determine the position, . . .

§. III. Of the prognosis, ....

§. IV. Of the attentions necessary for the woman in labor,

ARTICLE in.

SECTION 1.

Accidental Dystocia, ... . . . . 369

XX CONTENTS.

§. I. Of hemorrhagic dystocia, .... 369

§. II. Of convulsive dystocia, .... 385

§. III. Dystocia caused by premature descent of the umbilical cord, ...... 395

§. IV. Dystocia from excessive length or shortness of the

umbilical cord, ..... 398

§. V. Aneurismal dystocia, .... 400

§. VI. Dystocia from asthma, hydrothorax, gibbosity, dropsy, 400

§. VII. Hernial dystocia, ..... 401

§. VIII. Dystocia from syncope, .... 401

Essential Dystocia, ...... 403

§. I. Dystocia occasioned by the state of the female organs, 403

§. II. Dystocia depending on the foetus, . . . 413

Dystocia from Wrong Presentations of the Foetus, . . 418

§. I. Deviated positions of the head, . . . 418

§. II. Deviated breech positions, . . . . 419

§. III. Deviated positions of the trunk of the body, . . 419

CHAPTER VI. Obstetric Operations, ...... 427

ARTICLE I.

SECTION 1.

Of Turning in General, ...... 428

SECTION 2.

Of Version by the Head, ..... 434

SECTION 3. Of Turning by the Feet or Pelvis, .... 437

§. I. Of bringing down the feet when the head is at the

CONTENTS.

XXI

A. Left occipito-iliac position, . . . 441

B. Right occipito-iliac position, . , . 449 §. II. Of turning by the feet in presentations of the trunk, . 450

A. Positions of the shoulder and side, . . . 451 First; positions of the left shoulder, .... 451 Second ; positions of the right shoulder, .... 454

B. Presentation of the sternum, . . . 455

C. Presentation of the back, .... 455

SECTION 4. Of the Manoeuvre in Presentations of the Pelvis, . . 456

A. Positions of the feet, .... 457

B. Positions of the breech, .... 459

SECTION 5. Presentation of the Arm, . ..... 461

General Recapitulation on the Manoeuvre, . . . 465

ARTICLE IL

Of the Forceps, ....

SECTION !.• The Forceps in itself considered,

Of the Use of the Forceps,

§. I. Occipito-anterior position, .

§. II. Occipito-posterior position, .

§. III. Left occipito-iliac position,

§. IV. Right occipito-iliac position,

§. V. Positions of the pelvis,

§. VI. The child is completely or partially double,

§. VII. The head separated from the body remains alone in

the pelvis, ..... §. VIII. Recapitulation on the employment of the forceps.

469 473

478 478 479 479

481 483

ARTICLE III.

Of the Lever, xxu

CONTENTS.

Of the Lever in itself considered,

Use of the Lever,

§. I. Use of the lever as a crotchet, §. II. Of the lever used as a lever, .

485 486 487

ARTICLE IV.

Of the Fillet, .

ARTICLE V.

Of the Locked Head,

ARTICLE VI.

Of the Measures rendered necessary by Narrowness of the Pelvis, 494

Section 1

Of Regimen as a means of enabling Women with Contracted Pelvis to be delivered without the assistance of any surgical operation, . . , , . 497

Of Abortion brought on for the purpose of rendering symphyseotomy or the Cesarean Operation unnecessary, . 497

CHAPTER VII. Of the Natural Phenomena which follow the Delivery of the

ARTICLE I.

Of the Delivery of the After-birth, .... 538

Of Simple or Natural Delivery of the After-birth, . . 538

SECTION 2.

Of Complicated Delivery of the After-birth, . . . 545

ARTICLE II.

Management of the Child, ..... 561

SECTION 1. Of the Foetus in a Healthy State, .... 561

§. I. Of tying and cutting the cord, . . . 561

§. II. Of cleansiug the child, .... 566

§ III. Of dressing the child, .... 568

Of the Fcetus in a State of Disease, .... 569

§. II. Of the apoplectic state, .... 574

§. III. Of some other states of the new bom child, . . 576

Management of the Lying-in Woman, .... 578

I

AN ELEMENTARY

TREATISE ON MIDWIFERY

Chapter I

Of the Parts that are concerned in Generation^ Preg' nancy, and Labor.

ARTICLE I.

Of the Pelvis.

1. The pelvis, a sort of bony girdle or cavity, which constitutes the inferior termination of the trunk of the body, is found, in the human species, between the spine, which it supports posteriorly, and the thigh bones, on which it rests anteriorly. Its shape, which is very irregular and difficult to describe, resembles in some measure that of a cone with its apex and base strongly inclined towards each other, on their anterior face. Regarding it as an appendage both of the vertebral column and of the inferior extremities, the anatomists who lived antecedently to the time of Vesalius, gave no particular description of it. Diemerbroeck, Dionis, Saint Hilaire, Mauriceau, and De La Motte scarcely dwell for a moment upon it in their works: and even at the present day, the learned who aim to promote the honor of what is called philosophical anatomy, have, for the major part, returned in this respect to the same way of thinking as the ancient naturalists. But although the development of the skeleton might, in a system of general zoology, permit us to take 3 such a view of it, it does not follow that we ought to do so in tokology. The accoucheur must necessarily study the pelvis as a portion distinct from, and, as far as connected with his art, independent of the rest of the body. Hence it is, that all authors since the time of Smellie and Levret have followed this course; which I shall accordingly adopt.

SECTION 1.

Of the Bones of the Pelvis.

2. There are four bones in the adult pelvis: the sacrum and coccyx posteriorly, and on the median line; and the coxal bones in front, and on the sides. As he who is destined to engage in the practice of midwifery ought to be made acquainted with the entire pelvis, I do not deem it necessary to dwell at length upon the graphic details that are to be found in most of the classical works upon each constituent portion of it. On this subject there exists, even in our most modern works, quite a faulty mode of exposition, which it is proper to reform: after the manner of Baudelocque, the pubis, the ilium and ischium are minutely described as so many separate bones, while, for the most part, the coxal bone is almost entirely lost sight of; and yet it alone possesses any considerable interest in relation to midwifery, inasmuch as the three pieces of which it is composed are united into one before the individual is liable to become pregnant.

§. I. Of the Sacrum {os sacrum, s. clunium).

3. The sacrum, a single bone, situated between the last lumbar vertebra and the coccyx, is locked in, as it were, between the two ossa ilia.

4. Of a triangular or pyramidal shape, curved forwards on its anterior surface, it presents to the examiner, successively, an internal or pelvic region, and external or posterior region, two edges, a base and an apex.

5. Its anterior surface, somewhat concave, presents, 1. Along its middle, four or five quadrangular facettes, and the same number of transverse lines; 2. Outwardly, the five anterior sacral holes, terminating in an equal number of converging grooves, for the passage of the anterior branches of the sacral nerves; 3. More outwardly still, and between these openings, certain rough, uneven surfaces, for the attachment of the pyramidal muscles.

6. Its posterior surface, which is convex and very uneven, exhibits, along its middle, a series of protuberances which, by their union, constitute the crista of the sacrum; above this crest is seen the opening of the sacral canal; below are the two branches formed by its bifurcation, the triangular space which terminates the spinal canal, and the tubercles or points called the horns of the sacrum. On either side of the false vertebral spines, are seen the sacral grooves, the posterior sacral holes, and still nearer to the edges of the bone are to be found certain rough surfaces that serve for the attachment of the posterior sacro-iliac ligaments.

7. Its edges may be divided into two portions: one, superior, very thick, exhibits, on its anterior half, a semilunar articular facette which unites it to the coxal bone; on its posterior half, a hollow, and certain rough protuberances for the attachment of the sacro-iliac ligaments; the other, inferior, thin, almost sharp, serves for the insertion of the sacro-sciatic ligaments.

8. Its base, very broad, looks upwards. On its middle may be seen a plain elliptical surface, situated transversely, inclined more or less backwards, and which is articulated with the last lumbar vertebra; outwards, and a little forwards, a triangular surface, the lesser wing of the sacrum, which is slightly depressed towards its anterior face, and concurs in forming the internal iliac fossa; lastly, we observe on the posterior surface, the opening of the sacral canal, and the two articular apophyses of the first piece of the sacrum.

9. Its apex, thin, elliptical, slightly convex, is received into the base of the coccyx.

10. The sacrum, a simple prolongation of the spine, is formed by the union of five vertebrae. Near forty points of ossification may be observed in it; at birth it is still formed of fifteen pieces, three for each vertebra; but soon afterwards it only exhibits five, which, also, always coalesce before the age of puberty.

§. II. Of the Coccyx {ossa coccygis).

11. The coccyx is a sort of rudimental sacrum, whose anterior face almost plane, supports the end of the rectum, while its posterior surface, slightly convex, is only separated from the skin by the posterior sacro-coccygeal ligament. Its edges serve as points of attachment for the small sciatic ligament, and ischio-coccygeus muscle; its base, somewhat concave, surmounted laterally by two prolongations resembling horns, is articulated with the apex and cornua of the sacrum. Its apex, tubercular and rounded, gives insertion to the external sphincter of the anus.

12. The three or four pieces of which it is composed, mere vestiges of an equal number of vertebral bodies, remain for a long while movable upon each other; however, they at length coalesce; but, in most women, the bone, as a whole, loses its power of moving upon the sacrum only at a very advanced age.

§. III. Of the Coxal bone (os coxalium).

13. The bone of the ilium, the hip bone, the nameless bone, or more properly, as was long ago indicated by Celsus, the coxal bone, situated between the femur and the sacrum, alone forms the two anterior and lateral thirds of the pelvis.

14. Of an irregular quadrangular shape, looking as if strangulated at its middle, and twisted in two opposite directions, the coxal bone exhibits two surfaces and four edges.

15. On its internal or pelvic surface, which is divided into two nearly equal portions, we distinguish, above, a large excavation called the internal iliac fossa, which is filled by a muscle of the same name; behind, an articular surface, of a semilunar shape, called the articular facette; still farther behind, certain rugosities, similar to those observed on the edge of the sacrum, with which they unite.

On its inferior half, and posteriorly is seen a plane, almost triangular surface, which corresponds to the cotyloid cavity, and to the body of the ischium; in its middle, the sub-pubal opening; in front, the internal face of the pubis, and of the ischio-pubal ramus.

16. A semicircular edge, thick, smooth, and rounded posteriorly, thin and sharper in front where it terminates in the crista of the pubis, an edge which forms the greatest part of the superior strait, and unites these two halves of the pelvic surface of the coxal bone.

17. Its external or femoral surface exhibits, on its upper half, what is called the external iliac fossa, filled by the three glutei muscles; below, the sub-pubal hole, the external face of the ischium and ischio-pubic ramus; in the middle, the cotyloid cavity.

18. Its upper edge, or the iliac crista, thicker both posteriorly and anteriorly than in the middle, twisted like an italic s, divided by the anatomists into an external lip, an internal lip, and an interstice, for more conveniently describing the attachment of muscles, terminates in front, by the anterior-superior spine of the ilium, and behind, by the postero-superior spine of the ilium.

19. Its lower edge presents three portions; superiorly, an oval surface for the articulation of the pubes; inferiorly, the tuberosity of the ischium; and in the middle, the edge of the ischio-pubic ramus, turned somewhat outwards.

20. On its anterior edge, proceeding from above, downwards, and from the ilium towards the pubis, we remark the superior iliac spine; a small semilunar notch; the inferior iliac spine; the groove for the psoas and iliac muscles; the ileo-pectineal eminence, for the insertion of the lesser psoas; a triangular surface, smooth, inclined forwards, and concealed by the pectinalis muscle; the crest; then the spine of the pubis; and, lastly, the angle of the pubis.

21. On its posterior edge, in proceeding from above doAvnwards, is seen the posterior superior spine of the ilium; a small irregular notch; the postero-inferior spine of the ilium, which articulates with the sacrum; the great ischiatic notch; the ischiatic spine; the small ischiatic notch, and the most posterior portion of the tuberosity of the ischium.

22. At birth, the coxal bone is composed of three distinct pieces: one superior, the ilium, which constitutes the hip and the two iliac fossa; one inferior, the ischium, which supports the weight of the body when seated; the third, anterior, the pubis, to which are appended, as it were, the organs of generation. It is in the cotyloid cavity, at the ileo-pectineal eminence, and in the middle of the ischio-pubal ramus, that these three bones at length are blended into one about the period of puberty; but there are commonly added in childhood, a plate for the crest of the ilium, one for the tuberosity of the ischium, another point of ossification for the antero-inferior spine, and a fourth for the spine of the pubis; which sometimes do not coalesce with the principal pieces until a very late period.

SECTION 2. Of the Articulations, or Symphyses of the Pelvis

23. There are three principal articulations of the pelvis: one for the two pubes in front, and two for the bones of the ilium and the sacrum behind.

24. At the anterior or median symphysis, the bones are kept in contact by a fibro-cartilaginous substance called the interpubal ligament, and whose thickness is far from being uniform at every point of the kind of ring or oval circle which it represents. Its thickness, which is very considerable on the upper part, a little less so in front, and much less so behind, becomes suddenly much greater below, where the fibrous body assumes the name of sub-pubal or triangular ligament. In the centre, the articular surfaces are separated by a very thin plate of cartilage, which in early life, and even in a good many adult women, is moistened by a small quantity of synovial fluid.

A portion of the periosteum lines the posterior surface, a fibrous lamina of the same material is observed in front, and these two layers

3* have received the names of anterior and posterior ligaments of the symphysis pubis.

25. The sacro-iliac or posterior symphyses are much more complex than the preceding. There the sacrum is locked, like a double wedge, between the coxal bones, so that it offers a very efficient resistance to the weight of the body, which presses it from above downwards, and to the efforts of the pelvic viscera, which tend to force it backwards; its articular surfaces, although uneven, are nevertheless covered with a very thick diarthrodial cartilage, while those of the iliac bones are wholly destitute of them.

26. The name of posterior sacro-iliac ligament is given to a collection of fibrous bundles, that are yellow, elastic, mixed with small lumps of fat which fill up the uneven and rugous excavation that is seen behind the cartilaginous surfaces. These fibrous bundles of the same nature with the yellow ligaments of the vertebrae, are composed of fibres decussating in every direction, and are united almost intimately with the sacrum and coxal bones. Being of considerable strength, they give an extraordinary solidity to the articulation which they concur in forming. There is not, rigorously speaking, any anterior sacro-iliac ligament: a simple lamella of the pelvic periosteum serves in its stead.

27. Other small fibrous bands also serve, but less immediately, to unite the bones of the pelvis behind. These are the sacro-sciatic, and sacro-spinal ligaments; which, by passing from the posterior spines of the ilium, and from the inferior half of the edge of the sacrum to the spine, and tuberosity of the ischium, convert the two ischiatic notches into holes.

28. The connections of the pelvis with the vertebral column and with the coccyx, are effected by two amphiarthroses.

2\h One, the sacro-coccygeal articulation, is composed, 1. Of an elliptical fibro-cartilaginous lamina, which unites the point of the sacrum to the base of the coccyx; 2. Of the posterior sacro-coccygeal ligament, a sort of prolongation or extension of the supra-spinal ligament of the vertebrae, which closes the lower extremity of the sacral canal; and 3. Of the anterior sacro-coccygeal ligament, formed of two lateral bands united at their point on the front of the second or third piece of the coccyx. Naturally very movable in women, this articulation permits the coccyx to turn backwards, from half an inch to an inch, while the child is passing through the lower strait.