Part 2

Nomenclature.--The question of nomenclature has been one of difficulty. What is desired is a uniform set of anatomical names,--a system that shall be generally used by anatomists. At present the greatest diversity prevails as to the names to be applied to the different structures of the body. The only set of terms which at the present time seems to have any chance of general acceptance is that proposed by the German Anatomical Society at their meeting in Basel in 1895, and generally designated by the abbreviation BNA. This system has therefore been adopted, in its main features, for use in the present work. It seems impossible at the present time, however, to impose any one set of terms absolutely upon anatomists of all nations, and we have felt it necessary to use for certain familiar structures, in place of the BNA terms, names that have come to have a fixed place in English anatomy, and may almost be considered component parts of the English language. The German anatomists have expressly recognized the fact that this would be to a greater or less degree necessary among anatomists of different nations, and have characterized their list as for the present tentative, and capable of farther development. The only purpose of a name is that it shall furnish a key to a common understanding; where the BNA name does not furnish such a key to English readers, and where there is a term in established English usage that does serve this purpose and seems unlikely to be supplanted, we have used the latter. But we have endeavored to make the number of these exceptions as small as possible, and in such cases we have usually cited at the same time the term proposed by the German society, followed by the abbreviation BNA. When, on the other hand, we have adopted a BNA term for which there is also a commonly used English equivalent, the latter has likewise usually been cited in parenthesis.

In deciding whether or not to use in a given case the BNA term many difficult cases arose. Will the common English name innominate bone (os innominatum) be replaced by the BNA term os coxæ or coxal bone? We have held this to be highly improbable, and have therefore used the term innominate bone, merely citing os coxæ (BNA) as a synonym. In the same way we have used centrum as a designation of a part of a vertebra, in place of corpus (BNA); premaxillary bone or premaxilla in place of os incisivum (BNA); malar bone in place of os zygomaticum (BNA); trapezoid as a name of one of the bones of the carpus, in place of os multangulum minus (BNA), etc. In other cases where it has seemed probable that the BNA term would come into common use, though now unfamiliar, this and the more common English expression are both used or used alternatively; such has been the case, for example, with the Gasserian ganglion or semilunar ganglion (BNA). In naming the cerebral sulci and gyri the system in use for man is not well fitted for bringing out the plan of those in the brain of the cat, so that it was necessary to reject the BNA names for these structures.

As to the use of the Latin terms and their equivalents in English form, we have made a practice of employing in the text sometimes one, sometimes the other; this has the advantage of giving variety, and of impressing the interchangeability of the Latin and English forms on the mind of the student. Where a given structure is called by two equally well-known names, we have used both, holding that the student should become familiar with each and recognize their identity of meaning.

In general we have maintained the principle that the primary purpose of such a work as the present is not to illustrate or defend any particular system of nomenclature, but to aid in obtaining a knowledge of the structures themselves. With this end in view, we have used such terms as would in our judgment best subserve this purpose, making the BNA system, as the one most likely to prevail, our basis. In applying the system we have had to keep in mind a number of sometimes conflicting principles. In some cases the judgment of other anatomists will doubtless differ from our own; but this we feel to be inevitable. The matter of an absolutely uniform nomenclature is not ripe for settlement at the present time.

Some further explanation is needed in regard to the topographical terms, or terms of direction, used in the present work. We have adopted the BNA terms in this matter also. The terms superior, inferior, anterior, and posterior have been avoided, as these terms do not convey the same meaning in the case of the cat as they do in man, owing to the difference in the posture of the body. In place of these terms are used dorsal and ventral, cranial and caudal. As terms of direction these, of course, must have an absolutely fixed meaning, signifying always the same direction without necessary reference to any given structure. For example, cranial means not merely toward the cranium, but refers to the direction which is indicated by movement along a line from the middle of the body, toward the cranium; after the head or cranium is reached, the term still continues in force for structures even beyond the cranium. Thus the tip of the nose is considered to be craniad of the cranium itself. Lateral signifies away from the middle plane; medial toward it. Inner and outer or internal and external are used only with reference to the structure of separate organs, not with reference to the median plane of the body.

In describing the limbs the convexity of the joint (the elbow or knee) is considered as dorsal, the concavity being therefore ventral. Medial refers to that side of the limb which in the normal position is toward the middle of the body; lateral to the outer side. Terms of direction which are derived only from the structure of the limb itself are in some cases more convenient than the usual ones. In the fore limbs the terms radial (referring to the side on which the radius lies) and ulnar (referring to the side on which the ulna lies) are used; in the hind limbs the terms tibial and fibular are used in a similar manner. Distal means toward the free end of a limb or other projecting structure; proximal, toward the attached end.

For all these terms an adverbial form ending in -ad has been employed. Experience has shown this to be very useful in practice, and while not expressly recommended by the BNA, it is not condemned. Terms ending in -al are therefore adjectives; those ending in -ad are adverbs.

In compounding these terms of direction, the hyphen has been omitted in accordance with the usage recommended by the Standard Dictionary. Thus dorsoventral is written in place of dorso-ventral, etc. The student will perhaps be assisted in understanding these compounds if he notes that the first component always ends in -o, so that the letter o practically serves the purpose of a hyphen in determining how the word is to be divided.

In one particular the BNA nomenclature is not entirely consistent. While recommending or at least permitting the use of the general terms dorsal and ventral in place of the human posterior and anterior, and cranial and caudal in place of superior and inferior, it retains the words anterior, posterior, superior, and inferior as parts of the names of definite organs. For example, we have the muscle serratus anterior in place of serratus ventralis; serratus posterior inferior in place of serratus dorsalis caudalis. This is very unfortunate, from a comparative standpoint, but we have felt it necessary to retain the BNA terms in order that the structures of the cat may receive the same names as the corresponding structures of man.

In the matter of orthography we have endeavored to follow the best English anatomical usage, as exemplified in Gray’s Human Anatomy,--therefore writing peroneus in place of peronæus, pyriformis in place of piriformis, etc.

The book is designed for use in the laboratory, to accompany the dissection and study of the structures themselves. Anatomy cannot be learned from a book alone, and no one should attempt to use the present work without at the same time carefully dissecting the cat. On the other hand, anatomy can scarcely be learned without descriptions and figures of the structures laid bare in dissection, so that this or some similar work should be in the hands of any one attempting to gain a knowledge of anatomy through the dissection of the cat.

The figures have all been drawn from actual dissections, and have been carefully selected with a view to furnishing the most direct assistance to the dissector. It is hoped that no figures are lacking that are required for giving the students the necessary points of departure for an intelligent dissection of any part of the body. The fore limb is illustrated somewhat more fully than the hind limb, because it was thought that the fore limb would usually be dissected first; the hind limb will be easily dissected, with the aid of the figures given, after the experience gained in dissecting the fore limb.

As the book is designed to accompany the dissection of the specimen in the laboratory, it was deemed best to give succinct specific directions for the dissection of the different systems of organs, together with suggestions as to methods of preserving and handling the material. These are included in an appendix.

CONTENTS.

PAGE THE SKELETON OF THE CAT 1

I. The Vertebral Column 1 Thoracic Vertebræ 1 Lumbar Vertebræ 7 Sacral Vertebræ: Sacrum 8 Caudal Vertebræ 11 Cervical Vertebræ 11 Ligaments of the Vertebral Column 16

II. The Ribs 18

III. The Sternum 20

IV. The Skull 21 Occipital Bone 22 Interparietal 25 Sphenoid 25 Presphenoid 29 Temporal 30 Parietal 36 Frontal 37 Maxillary 39 Premaxillary 41 Nasal 42 Ethmoid 42 Vomer 44 Palatine 45 Lachrymal 46 Malar 47 Mandible 47 Hyoid 49 The Skull as a Whole 49 Cavities of the Skull 57 Joints and Ligaments of the Skull 61

V. The Thoracic Extremities 62 Scapula 62 Clavicle 64 Humerus 64 Radius 67 Ulna 68 Carpus 69 Bones of the Hand 71 Joints and Ligaments of the Thoracic Limbs 73

VI. The Pelvic Extremities 76 Innominate Bones 76 Femur 79 Patella 80 Tibia 80 Fibula 82 Tarsus 82 Bones of the Foot 85 Joints and Ligaments of the Pelvic Limbs 86

THE MUSCLES 93

I. Muscles of the Skin 93

II. Muscles of the Head 96 A. Superficial Muscles 96 B. Deep Muscles 107 a. Muscles of Mastication 107 b. Muscles of Hyoid Bone 112

III. Muscles of the Body 115 1. Muscles of the Back 115 A. Muscles of the Shoulder 115 B. Muscles of the Vertebral Column 123 a. Muscles of the Lumbar and Thoracic Region 126 b. Dorsal Muscles of the Cervical Region 131 C. Muscles of the Tail 136 2. Muscles on the Ventral Side of the Vertebral Column 138 A. Lumbar and Thoracic Regions 138 B. Muscles on the Ventral Side of the Neck 139 3. Muscles of the Thorax 144 A. Breast Muscles (Connecting the Arm and Thorax) 144 B. Muscles of the Wall of the Thorax 148 4. Abdominal Muscles 153

IV. Muscles of the Thoracic Limbs 156 1. Muscles of the Shoulder 156 A. Lateral Surface 156 B. Medial Surface 161 2. Muscles of the Brachium or Upper Arm 164 3. Muscles of the Antibrachium or Forearm 172 Fascia of the Forearm 172 A. Muscles on the Ulnar and Dorsal Side of the Forearm 173 B. Muscles on the Radial and Ventral Side of the Forearm 179 4. Muscles of the Hand 184 A. Between the Tendons 184 B. Muscles of the Thumb 184 C. Between the Metacarpals 185 D. Special Muscles of the Second Digit 185 E. Special Muscles of the Fifth Digit 185

V. Muscles of the Pelvic Limbs 186 1. Muscles of the Hip 186 A. On the Lateral Surface of the Hip 186 Fascia of the Thigh 186 B. On the Medial Surface of the Hip 192 2. Muscles of the Thigh 194 3. Muscles of the Lower Leg 203 A. On the Ventral Side 203 B. On the Dorsal and Lateral Surfaces 209 4. Muscles of the Foot 212 A. Muscles on the Dorsum of the Foot 212 B. Muscles on the Sole of the Foot 212 C. Muscles of the Tarsus 215

THE VISCERA 217