First lines of physiology, being an introduction to the science of life; written in popular language

Introduction To The Science Of Life

WRITTEN IN POPULAR LANGUAGE.

DESIGNED FOR THE USE OF

COffllON SCHOOLS, ACADEMIES, AND GENEEAL READERS.

BY REYNELL COAXES, M.D.

AUTHOR OF THE FIRST LINES OF NATURAL PHILOSOPHy.-

SIXTH EDITION, REVISED;

WITH AN APPENDIX

Entered according to Act of Congress, in the 3'e:ir 1845, by Reyneix CoATEs, M. D., in llie Clerk's Office of the District Court for the Eastern Diistrict of Pennsylvania.

£ ftr^

J. FAGAN, STEREGTYPER.

TO A. CRITTENTEN, ESQ.

PRINCIPAL OP THE ALBANY FEMALE ACADEMY.

In just admiration of the talent which conducts to such noble results, the system of instruction under his immediate superintendence — as proved by both the mental culture and the manners of his pupils,

THIS VOLUME l^ft aac»j)ectfiill2 JBetricatetr,

BY THE AUTHOR.

Preface

To the earlier editions of this little work, several pages of prefatory matter appeared requisite, in order, partly, to apologize for the introduction of a new candidate for popular favour, in a department of science for which several introductory text-books adapted to the use of schools and unprofessional readers had been previously produced, and, partly, to defend the fitness of Physiology as a branch of elementary education, not only for male children, but for females also.

This necessity is no longer obvious. The rapid succession of reprints which the work has undergone furnishes abundant evidence that it is calculated to supply a deficiency in our means of instruction which is felt and acknowledged by the public ; and the author has received, from t]\e publishers, the gratifying assurance that an ample share of the patronage bestowed upon it has been derived from the female schools and academies of the country. He has, therefore, been induced to apply to more useful purpose the chief part of the space formerly devoted to the preface; and now, after very careful revision, the addition of a glossary, and a slight change of title, he no longer fears the charge of immodest presumption in presenting the volume to teachers and general readers who have not as yet examined its contents, as a treatise that has been tested and approved upon authority less questionable than his own.

Many essays designed for similar purposes are ushered into the world with lofty pretensions as to the perfect manner in which the whole field of Physiology is covered within their pages. This pretension is an insult to the understanding of the reader; and in the present undertaking, the author pretends to nothing more than the presentation of such

1 * (5)

VI PREFACE.

a general view of the science as he conceives to form a legitimate portion of a strictly elementary education — such a view as will enable the pupil, in after life, to comprehend and to enjoy those profounder works on natural history, hygiene, the fine arts, and even morals, which, without some knowledge of Physiology, are either altogether unintelligible, or vaguely understood.

The practical teacher will find the references to the matter, whether in the Contents, the body of the work, the Questions, or the Glossary, arranged according to the numbers of the paragraphs, and not those of the pages. The Questions have been placed at the end of the text, rather than the bottom of each page, with the express intention of testing more perfectly the comprehension of the pupil ; and they are so worded as to render almost impossible the indulgence of the parrot-like propensity to answer in the precise words of the writer. The Glossary follows the Questions, and concludes the volume. It will be found interesting to those who are fond of impressing technicalities upon the memory by the aid of associations connected with their derivation, and will prove a useful guide to the correct pronunciation, as well as the true meaning of the few professional terms which have been unavoidably employed.

The character of the volume being that of a regular treatise, and not a mere compilation, it will be reasonably expected that opinions peculiar to the writer may occasionally appear. This introduction of novelty, so far as the predicates are concerned, has been studiously avoided; but, in the chain of the argument, conclusions strictly logical, and therefore indisputable, have not been suppressed, mert^ly because they have not been embalmed in the dust of the library.

Chapter I

OiN THE iMOTION AND GROWTH OF ANIMATE AND INANIMATE THINGS.

Paragraph What constitutes the difFerence between things which have life

and things which have not, 1

Motion is not a proof of life, nor is its absence a proof of the

absence of life, 2

Illustrations. — The sleeping- dog — the moving watch 2

The stillness of the trees in the absence of wind — the

seeming vitality of the eye-stone, 3

Growth is not a proof of life, 4, 5

Illustrations. — The confused ideas of children on this subject — growth of spars in caves — of saltpetre, mould, and mosses

in damp places — of iron ore in swamps, 8

Folly of supposing that rocks and stones have an inherent power

of growth, 9

Motion and growth are insufficient to distinguish animate from

inanimate things, 10

Birth and death are not inherent properties of living things, .... 11

Inanimate things cannot move by their own energy, but must be

moved by other things, 13

Illustrations. — Motion of a falling stone — a vibrating spring

— the eye-stone, 13

Living things are moved by other things ; but have also other

powers of motion, 14

Illustrations. — A man falling by gravity — the limb of a tree

vibrating when bent, 14

Inherent power of motion in living things, 15

Illustrations. — Motions of a potatoe sprouting in the dark, 15 Motions of leaves and flowers towards the light — motions

observed in DionoBa muscipula, 16

Motions of animals determined by will, 17

First distincth'e property of living things — the power of regulating

their own motions, 18

Explanation of the word organ, 19

of the term organized beings, 20

of the term organization, , 20

Division of matter into organic and inorganic matter, 22

Xll CONTENTS.

Paragraph Explanation of the terms petrifaction and organic remains — 23

of the terra system, 24, 25

Difference in the mode of growth of animate and inanimate

things, 26

Inanimate things grow by additions to tlieir exterior, 27

liiving things grow by additions to their interior, 28, 29

Illustrations. — Tlie formation of sap and blood, 30

Living things construct their own particles, 31

Organized beings possess the power of moving their own fluids, 32 Apparent growth of inanimate things by internal additions explained, 33

Illustrations. — Experiment of a sponge in water,. . . ■ 33

Experiment of a hyacinth growing in water, 34

Experiment of iron swelled by heat, 35

Independent powers of motion in living things, 36

Our ignorance of the nature of life, 37

CHAPTER XL

ON THE INDIVIDUALITY OF ORGANIZED BEINGS, AND THE DIFFUSION OF LIFE IN LIVING BODIES.

Peculiar powers of life enjoyed by every organ, 38

Explanation of the terms function and vital functions, 39

The mutual dependence of parts and their functions, • . . 40

The various degrees of importance of different organs, 41

The power of healing injuries is inversely as the complexity of

the organization, 42, 43

Illustrations. — Life in the amputated tail of a snake, the hind legs of frogs, and the heads of turtles — life in tortoises

without brain or heart, and in the disembowelled shark,. . 45

Diffusion of vital power in simple animals, 46

Organization of animal and vegetable fluids — explanation of the

term assimilation, 47

Tiie nutritive fluids are possessed of life, 48

The simplicity of the fluids corresponds with the simplicity of

the solid structure of organized beings, 49-51

Illustration. — History of a medusa, 52-55

Independent life of pieces cut from animals of very simple organization, 56

History of the hydra viridis — the type of simphcity in animal

organization, 57

Digestion in the hydra, 58

Absorption in the hydra, •. 59

The great cavity of the hydra answ^ers the double purpose of

a stomach and a heart, 60

The hydra, when inverted, continues to live, 61

Multiplication of the hydra by artificial division, 62

Spontaneous division of the hydra, 63

CONTENTS. Xlll

Limits of the divisibility of the hydra, 64

Uniformity of structure in the hydra, 65

Explanation of the terms cellular membrane and cellular tissue, . 66, 67

Structure of cellular tissue, 68

Illustrations. — Inflation of fowls for market, 69

Effects of a fractured rib wounding the lungs, 70

Structure of fat — explanation of the term adipose tissue,. 71

Vital functions of the hydra, 72-77

Animals distinguished from vegetables by consciousness and

vfilL 78

Chapter III

ON THE ORGANIZATION AND FUNCTIONS OF SIMPLE ANIMALS, APPARENTLY DIVESTED OF SPECIAL ORGANS.

Minuteness of simple beings necessary to the preservation of the

race, 79

Simple beings — why confined to fluids, 80

Fixedness of many simple animals — their means of taking prey —

tentacula?, 81

Means of taking food — cilia, 82

Cilia and tentaculae of flustra carbacea, 83

Cilia are sometimes organs of locomotion — vorticella cyathina, . . 84

Contractility — motion of cilia not muscular, 85

Motion of cilia in respiration of larger animals, 86

Cilia in plants — chara hispida, 87

Gemmules — gemmules of flustra, 88

Polypi commonly live in families and have a common life, 89

Necessity for mechanical support in simple animals, 90

Several forms of calcareous or horny support, 91

Madrepore — effects on navigation, 94

Secretion — as seen in polypi, cuticle, shells, &c., 96

of lime and horn common to all animals and, probably,

to parts of animals, 98

Nutrition a kind of secretion, 99

Secretions sometimes act as motive powers — bile, 100

Functions of organic and animal life, 101

Contractility moves the fluids, 103

differs from inorganic contraction, which is the

result of cohesive attraction, 104

instances of — visible in plants and as displayed in

physalia megalista, 105

mode of taking prey in physalia, and its mode of

locomotion, 106

not necessarily dependent on will, 110

must be excited by some agent, 112 ,

Contraction results from the action of stimulants, 113

Tonicity, 114

diminished or destroyed by paralysis, fainting and sleep, 116

XIV CONTENTS.

Paragrapli

Tonicity — influenced by heat and cold, 117

of skin, 118

Various forms of tonicity — are they all due to the same cause?. 119

Chapter IV

ON THE NECESSITY FOR A MASTICATORY AND DIGESTIVE APPARATUS IN COMPLEX ANIMALS.

Simplicity of the elementary stomach, 121

Necessary division of the stomach in the medusa, 122

The ramifications of the stomach in medusa seem to supply the

place of blood-vessels, 123

Necessity for greater complexity as we ascend the scale — masti-

catory apparatus, 124

Early appearance of teeth and jaws — teeth and jaws in echinoder-

mata and in insects, 125

Internal masticatory organs, 126

Alimentary canal, 127

Gizzards, 128

Digestive apparatus — more simple in carnivorous animals, 130

of shell-fish complex, 131

simple in birds of prey, and complex in

beasts that live on vegetables, 132

Chapter V

ON THE NECESSITY FOR A SPECIAL APPARATUS OF MOTION. THE MUSCULAR AND OSSEOUS SYSTEMS AND THEIR APPENDAGES.

Necessity of a muscular system, ] 33

Muscular system, 134

Muscles of voluntary motion, 135

Necessity and existence of involuntary muscles, ] 36

Muscles of organic and animal life, 137

Mixed muscles, 138

Fascia, 139

Fascial system, 140

Uses of fasciae, 141

Structure of fascia, 142

Appearance of muscles — they are identical with flesh, 143

Arrangement of separate muscles, 144

Structure and colour of muscles, 146

Muscular fibre — structure of, 148

Cellular nidus of muscles, 149

Muscles between fragments of bone reduced to cellular tissue, . . 150

Attachments of muscles, 151

Cutaneous and fascial attachments of muscles, 151

Testaceous attachments, 152

CONTENTS. XV

Attachments in echinoderrnata, 153

Attachments in insects and Crustacea, 155

External skeletons and appendages of the skin, 156

Necessity for an internal skeleton in more complex animals —

osseous system — bones, 157

Attachment of voluntary and mixed muscles to bones, 158

Carlilai;i:inous condition of bones in young children and quadrupeds, and in certain fishes, 159

Earthy material of perfect bone, 160

Condition of bone when deprived of cartilage, 161

Condition of bone when deprived of earth 162

Reduction of bone to cellular tissue by art, 1 63

Reduction of bone to cartilage or cellular tissue by disease, 164

Ail organs reducible to cellular tissue, 165

Cellular tissue the constructor of all the organs, 166

Reunion of wounds always effected by cellular tissue, 167

The power of cellular tissue to form different organs is a mystery , 168

Necessity of cartilages at the joints, 169

Articular cartilages, 170

Synovial membranes and fluid, 172

Necessity for ligaments to bind the joints, 173

Structure and functions of ligaments, 174

The envelope of bones called periosteum, 175

Extent of the periosteum — explanation of the terms periosteum, perichondrium and pericranium, . 176

Recapitulation of the parts and appendages of the osseous

system, 177

Necessity for tendons or parts accessory to the voluntary muscles, 179

Form and arrangement of tendons, ISO

Involuntary muscles rarely have tendons — generally hollow —

muscular coat of alimentary canal, 181

Chapter VI. On The General Divisions Of The Vascular System

Necessity for the existence of blood-vessels, 182

Of the veins, 183

Tendency of the venous blood to a common centre. — Valves

of the veins, 184

Different forms of the common centre. — The heart, 185

Conduits for the blood running from the common centre or

heart, culled arteries, 186

Communication between the arteries and the veins. — The

capillaries, 187

The circulation, 188

Gradual developement of distinct systems of organs as the

scale of animal organization rises, 189

XVI CONTENTS.

Paragraph Partial circulation in insects, 190

Circulation, in the earth-worm, leech, marine worms, and

shell-fish, 191

Ahment in the hydra, &c. taken into the body by imbibition, . . . 192 The absorption of the nourishment from the chyme in insects,

worms, &c., is probably by a double imbibition, 193

Assimilation not complete when the nourishment or chyle is

first imbibed, hut is perfected in the blood-vessels, 194

Set of vessels, called the lactcals, for conveying the chyle to

the blood-vessels, 195

Colour and structure of chyle, 196

Origin of the lacteals. — Uncertainty of the question whether they absorb by imbibition. — Their resemblance to roots. —

Their structure and route to the veins, 197

The agency of the lacteals in destroying the power of independent life in the parts of the more complex animals when divided, 200 The lacteals not the only route by which substances from without find their way to the blood. — Cutaneous, cellular, and venous absorption by imbibition in the most perfect and

complex animals, 201

The lymphatics or absorbents. — Characters of lymph, 203

Proofs that the lymphatics convey substances to the blood, 204

Objection to the term absorbents, as applied to the lymphatics,. . 206

Chapter VII. Of The Functions Of Secretion, Respiration, And Nutrition

Recapitulation of the scale of gradual complication in the nutritive organs, 207

Question why food is required to support the frame after an

animal has reached maturity', 208

Waste by perspiration in plants and animals. — Insensible perspiration, 209

Perspiration from the cavities. — Moisture of breath, 210

Respiration considerable in amount. — A secretion furnished

from the blood, 211

Waste of the blood by the numerous secretions. — Much food

required to compensate it, 212

Many fevers diminish the secretions and the waste of the circulation — hence the impropriety of giving much food in fevers, 213

During starvation a man lives on himself, 214

Diminution of all organs and the destruction of some less important ones, by abstinence, 215

All the particles discharged from the body are taken up by the absorbents, carried into the circulation, and discharged by secretion, 216

Absorption of particles carried on continually, even in health

CONTENTS. XVU

Paragraph — reasons why the size of the organs is not diminished thereby, — and why they grow larger during adolescence, 217

The particles of the whole body totally changed every few

years — lience the continued necessity for food, 218

The constant accumulation of worn-out particles in the blood requires a purification of that fluid. — This office performed

by means of the secretions, 219

Numerous secretions of complex animals, 220

Folly of reasoning on the ultimate causes of vital phenomena, 221 Arrangement of the blood-vessels in secreting organs. — Mucous membrane, 222

Secretory glands, 223

Arrangement of capillaries in secretory glands, 224

Structure of the ducts of the secretory glands, 225

Proofs of transpiration from the blood-vessels into the ducts of

glands 226

Economical uses made of many secretions — ^tears, saliva, and bile, 227

Of respiration, 228

Principal object of respiration,. 229

Principal ultimate elements of animal organization, 230

The surplus carbon of the blood requires to be discharged by a special apparatus. — Partly discharged by the liver in the

secretion of bile, but not sufficiently, 231

Carbon discharged from the blood in the form of carbonic acid, whenever the blood in living blood-vessels approaches very near to the atmospheric air. This product always produced by respiration, 233

Animals that live in water, respire the air combined with the

water, 234

Too great a supply of air kills a fish, and exposure to pure

oxygen soon kills the more perfect animals, 235

Actual contact with air not necessary to purify the blood. —

Respiration effected by imbibition, and transpiration, 236

Cutaneous respiration of the simpler animals, 237

Cutaneous respiration in man, 238

Mode of respiration by special apparatus, 239

Resemblance of respiratory organs to secretory glands, 240

Tracheal respiration of insects, &c., 241

Aquatic respiratory apparatus, 242

Branchial respiration, , 243

Great variety of form in branchiae — all constructed on one prin-

ciple, 244

Agency of cilia in branchial respiration, 245

Pulmonary respiration, 246

Simplest forms of pulmonary organs, 247

Arrangement of the lungs in the larger animals. — Right and left

lungs, 249

Structure of the air passages in such animals, 250

Names of the principal air passage and its ramifications, 251

Resemblance of air passage to the ducts of secretory glands. —

—Their structure, 253

XVlll CONTENTS.

Paragrapli

Apparatus of inspiration 253

Air passages in the bones of birds, 254

Pulmonary and branchial respiration of reptiles,. 255

Partial respiration of inferior animals, 256

Feebleness and slowness of vital functions in animals with partial respiration. — Amphibia, 257

Perfect respiration and activity of function in man, quadrupeds,

and birds, 258

Respiratory and nutritive vessels of the respiratory organs, and the distinct routes of circulation in them. — Nutritive and respiratory systems of vessels, 259

Systematic circulatory apparatus an objectionable term. — General or nutritive system or apparatus preferred, 260

Description of the heart, 261

Functions of the auricles and ventricles, 262

Description of the route of the circulation, 263

The heart is generally a double or quadruple organ, 266

The circulation of all animals is single and not double, 267

Interlacement of the blood-vessels. — Route of circulation when

vessels are obliterated, 268

Danger of an obstruction in a large artery. — Death of a part inevitable when the circulation through its vessels is totally

arrested for some time, 269

Not only the life, but the activity of function in a part, depends on the number and size of its blood-vessels and the quantity

of blood that passes through it, 270

Activity of the functions of muscles when compared with tendons. — Why the rapidity of the heart's action increases by

exercise — also the rapidity of the breathing, 271

Effects of exercise in enlarging muscles, 272

Effects of rest in diminishing or destroying them, 273

Generality of the law that habitual functional activity increases power, and habitual repose diminishes it in all the organs. —

Moral deduction, 274

Necessity for the alternation of repose and rest to promote

nutrition, 275

Of the effects of sleep at different ages, 277

Danger of over-exertion, and its effects on nutrition, 278

Effects of over-wrought labour and want of sleep 279

Agency of the organs themselves in perfecting assimilation,. . . . 280

Chapter VIII. On The Nervous System

The variety of vital actions often performed in producing a single effect, renders necessary a bond of communication

between the different organs, 281

First appearances of the nerves in the inferior animals, 282

Cineritious and medullary matter of the nervous system, 283

CONTENTS. XIX

Paragraph Structure of the brain, and the terminal connections of nervous

filaments, 284

Cellular tissue of the nervous system, 285

Nervous ganglia. — Nervous filaments of the brain and ganglia.

— Functions of the ganglia, 287

Structure and function of a nerve. — The neurilema, 289

Compound nerves with compound functions. — Each nervous

fibre a distinct organ with a special function, 291

()rigin and association of the nerves of motion and of feeling.

—Effects of dividing them, 292

Formation of a nervous plexus, 293

Forming and resulting nerves of ganglia, 294

Arrangement of nervous filaments in ganglia, 295

Influence of the ganglia upon the functions of the filaments, . . . 296 Complex structure of most organs. — Extensive diffusion of nervous filaments and nervous influence. — The functions of

<■ organs controlled by nerves, 297

Divisions of the nervous system. — Nervous systems of organic

and animal life, 299

Irregular distribution of the nerves of organic life, and irregular form of the organs controlled by them, 301

Regularity of the nerves of animal life and the organs controlled by them, 303

Position and curious functions of the great sympathetic nerve

in health and disease, 304

Dependence of the nerves upon the capillary blood-vessels, 311

Mutual dependence of all parts of the frame upon each other. . . 312 Difference of plan observed between the nervous systems of animals with an internal, and those with an external skeleton — Particularly in relation to the brain, 313

Still greater imperfection of the nerves in animals of yet lower

grade, 314

Consequent impossibility of comparing- the differences of intelligence between one great class of animals and another, by reference to the structure of the brain or nervous system, . 316 Remarks upon the impropriety of the term — The scale or chain

of animated nature, 318

Chapter IX. Of The Surfaces Of The Body

Great divisions of the human body into head, neck, trunk

and extremities, 319

Division of the head into the cranium and face, 321

Division of the trunk into chest, abdomen, and pelvis, 324

Divisions of the extremities, 328

Cellular structure of the whole body, 331

Of the integuments, 333

XX CONTENTS.

Paragrapb

Of the cuticle or epidermis, 336

Of the supposed pores of the skin, 340

Of the sebaceous folUcles, 342

Connections of the hair with the cuticle. — Growth of hair, 344

Functions of the cuticle, 348

Of the rete mucosum. — Of the colouring matter of the rete

mucosum, and the eflects of climate and seasons on the skin

and hair, 350

Of the true skin or cutis vera, 353

Of the structure and functions of cutis vera, and the papillae,. . . 355

Of the fleshy panicle or muscular layer of the skin, 358

Of the mucous follicles, 360

Connections of the skin. — Arrangement of the sub-cutaneous

cellular tissue and fat, 362

Universality of the covering of integuments, 365

Of the epithelium. — Inward reflections of the integuments. —

Modifications of the internal integuments, 366

Of the pharynx, and the muscular coat of the internal integuments, 368 Of the termination of the epithelium, and the structure of the

mucous membrane of the alimentary canal, 369

Of the villi, 371

Of mucous glands or collections of follicles, 372

Formation of the ducts of secretory glands by the integuments.

— Lining of the air passages, &c,, 374

Formation of accidental canals by the integuments, 375

Mutual convertibility of the internal and external integuments, . 376

Extent of the integuments and the surface, 379

Eflects of the absence of cuticle on the internal surface, 380

Concentration of sensibility at the origin of canals, 381

Vicarious action of the lungs and skin, 383

CPIAPTER X.

OF THE SKELETON AND ITS APPENDAGES.

Growth and general arrangement of the bones, 384

Tabular and cancellated structure of the cranium, 388

Walls, cellular structure and cavities of the long bones, 389

Cellular tissue of bone, and medullary membrane, 392

Structure of the solid portions of bone. — Use of the canals, 394

Blood-vessels of the bones, 395

Nervous sensibility of the bones, 396

A itality of bone proved by its diseases, 397

Bony structure of the head, 398

Form of tlie cavity of tlie cranium, 399

Of the frontal bone, 400

Of the frontal sinuses, 401

Of the orbitar plates, 404

Of the part of the brain covered by the frontal bone, 405

Of the parietal bones, 406

CONTENTS. XXI

Of the parts covered by the parietal bones, 407

Of the occipital bone, 408

Of the cuneiform process, 408

Of the great foramen, 409

Of the occipital cross, 410

Of the temporal bones, 413

Of the petrous portion of the temporal bone, 414

Of the ma«toid process of the temporal bone, 415

Of the sphenoid bone and cells, 418

Of the ethmoid bone, 419

Of the sutures, 420

Condition of the cranium during childhood, and its consequence, 421

Changes of cranium from the progress of age, 426

Good consequences of the arched form of the cranium, 427

Articulations of the cranium with the atlas vertebra, 428

Of the atlas vertebra, 429

Definition of the term condyle, 430

Articulations of the cranium and atlas with the vertebra dentata, 431

Of the limits of the motions of the head, 434

Of the bones of the face, 438

Of the upper jaw and its nerves, 439

Sympathetic connections between the teeth, the ear and eye, . . . 441

Of the teethi .' 442

Of the socket processes. — Of the enamel, 443

Of the periosteum of the teeth, 444

Of tooth-ache from inflamed periosteum, . . i 445

Of the absorption of the socket, . 446

Of the shedding of the infantile teeth, 447

Of the language of the teeth in relation to diet, 448

Of the sympathy between the stomach and the teeth, 455

Of the spine 457

Great divisions of the spine, 458

Of the bodies and processes of the vertebrae, 459

Of the articulations of the spine, and the intervertebral fibro-

cartilages, 461

Of the ligaments and spinal canal, 463

Of the mobility of the spine, 464

Of some effects of caries, rheumatism, &c. of the spine,. . . 466

Of the number and articulations of the ribs, 468

Of the cartilages of the ribs, 469

Of the sternum and its connections, 471

Of the motions of the ribs and sternum, 472

On some of the effects of mechanical restraint of those

motions, 475

Of the pelvis. — Of the sacrum, 480

Of the OS coccygis, 481

Of the ossa innominata, 482

Of the bones of the superior extremities, 483

Of the scapula and clavicle, 484

Of the shoulder-joint, 487

Of the humerus, 489

Of the elbow-joint, , 490

2*

XXU CONTENTS.

Of the ulna 491

Of the radius, 492

Of the motions of the forearm, 493

Of the wrist and hand, 494

Of the bones of the inferior extremities. Of the hip joint, 500

Of the head and neck of the fenmr and its changes, 501

Of the tibia and fibula, the patella and the knee-joint, 506

Of the ankle-joint, 509

Of the tarsal bones and bones of the foot, 510

Of the ligamentous and muscular support of the skeleton, 513

Of the effects of the inelasticity of certain parts of the skeleton, 514