. The cat : an introduction to the study of backboned animals, especially mammals. Cats; Anatomy, Comparative. 326 THE CAT. [CHAr. x. an. and lungs grow out from that canal ventrally. The renal and sexual organs arise close to the bifurcation of the ventral laminae into the somatopleures and splanchnopleures, and the limbs bud forth as rounded processes, the distal ends of which subsequently grow out into digits, while the limbs themselves become flexed in reverse directions. On each side of the body, close behind the head, certain apertures ap- pear, which lead from the exterior to what becom
. The cat : an introduction to the study of backboned animals, especially mammals. Cats; Anatomy, Comparative. 326 THE CAT. [CHAr. x. an. and lungs grow out from that canal ventrally. The renal and sexual organs arise close to the bifurcation of the ventral laminae into the somatopleures and splanchnopleures, and the limbs bud forth as rounded processes, the distal ends of which subsequently grow out into digits, while the limbs themselves become flexed in reverse directions. On each side of the body, close behind the head, certain apertures ap- pear, which lead from the exterior to what becomes the pharynx. These openings are the visceral clef is, and their interspaces are the visceral arches. Almost all the clefts disappear before birth. The formation of these various organs will be detailed subse- quently, but their relations to the three primary layers, from which the whole of them are built up, may be summarized as follows. The epiblast gives rise to the epidermis of the skin, the ner- vous centres, and the organs of sense. The hypoblast forms the epithelium of the alimentary canal, except its two ends, and of the glands which open into it. The mesoblast forms the in- ternal skeleton, the muscles, connective tissue, peritoneum and pleurae, and the vascular and secreting organs generally. It forms, therefore, the great bulk of the cat's body. § 6. During the whole process of development the germ is nourished by absorption. Within the Graafian follicle it profits by the cells of the discus proligerus and membrana granulosa, and when cast forth frorn its follicle into the cavity of the uterus it absorbs nutriment from the secretions of the uterine walls by processes, or villi, which grow forth on all sides from the surface of its chorion. It also feeds upon the contents of the umbilical vesicle, absorbing nutriment thence by the help of the vessels which there circulate, and which are at first of great relative size and importance. With *the development of the al
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectanatomy, bookyear1881
