THE ARTISTIC ANATOMY OF ANIMALS
INTRODUCTION
GENERALITIES OF COMPARATIVE ANATOMY
Of the animals by which we are surrounded, there are some which, occupying a place in our lives by reason of their natural endowments, are frequently represented in the works of artists—either as accompanying man in his work or in his amusements, or as intended to occupy the whole interest of the composition.
The necessity of knowing, from an artistic point of view, the structure of the human body makes clear the importance we attach, from the same point of view, to the study of the anatomy of animals—that is, the study of comparative anatomy. The name employed to designate this branch of anatomy shows that the object of this science is the study of the relative position and form which each region presents in all organized beings, taking for comparison the corresponding regions in man. The head in animals compared with the human head; the trunk and limbs compared to the trunk and limbs of the human being—this is the analysis we undertake, and the plan of the subject we are about to commence.
Our intention being, as we have just said, the comparison of the structure of animals with that of man, should we describe the anatomy of the human being in the pages which follow? We do not think so. Plastic human anatomy having been previously studied in special works,[2] we take it for granted that these have been studied before undertaking the subject of comparative anatomy. We will therefore not occupy time with the elementary facts relative to the skeleton and the superficial layer of muscles. We will not dilate on the division of the bones into long, short, large, single, paired, etc. All these preliminary elements we shall suppose to have been already studied.
This being granted, it is, nevertheless, necessary to take a rapid bird’s-eye view of organized beings, and to recall the terms used in their classification.
Animals are primarily classed in great divisions, based on the general characters which differentiate them most. These divisions, or branches, allow of their being so grouped that in each of them we find united the individuals whose general structure is uniform; and under the name of vertebrates are included man and the animals with which our studies will be occupied. The vertebrates, as the name indicates, are recognised by the presence of an interior skeleton formed by a central axis, the vertebral column, round which the other parts of the skeleton are arranged.
The vertebrate branch is divided into classes: fishes, amphibians or batrachians, reptiles, birds, and mammals.
The mammals—from the Latin mamma, a breast—are characterized by the presence of breasts designed for the alimentation of their young. Their bodies are covered with hair, hence the name pilifères proposed by Blainville; and, notwithstanding that in some individuals the hairs are few, the character is sufficient to distinguish them from all other vertebrates.