The animal kingdom, arranged after its organization : forming a natural history of animals, and an introduction to comparative anatomy . spine of the backand the ribs. The spine is composed of vertebrae moveable upon each other, of which the first supports the head, and which have an annular perforation, forming together a canal, wherein is lodged that medullary production ^ from which the nerves arise, and which is called the ^^^ ^•^^ ~ spinal marrow. The spine, most commonly, is continued into a tail, extending beyond the hinder limbs. The ribs are semicircles, which protect the sides of the
The animal kingdom, arranged after its organization : forming a natural history of animals, and an introduction to comparative anatomy . spine of the backand the ribs. The spine is composed of vertebrae moveable upon each other, of which the first supports the head, and which have an annular perforation, forming together a canal, wherein is lodged that medullary production ^ from which the nerves arise, and which is called the ^^^ ^•^^ ~ spinal marrow. The spine, most commonly, is continued into a tail, extending beyond the hinder limbs. The ribs are semicircles, which protect the sides of the cavity of the trunk : they are articulated at one extremity to the vertebrae, and are ordinarily attached in front to the breast-bone; but sometimes they only partly encircle the trunk, and there are genera in which they are hardly visible. There are never more than two pairs of limbs; but sometimes one or the other iswanting, or even both : their forms vary according to the movements which they have toexecute. The anterior limbs may be organized as hands, feet, wings, or fins; theposterior as feet, or instruments for Fig. 1. 36 VERTEBRATE ANIMALS. The blood is always red, and appears to have a composition proper for sustaining thatenergy of sentiment and vigour of muscles, but in ditferent degrees, which correspondto the amount of resinration, from which originates the subdivision of the vertebrateanimals into four classes. The external senses are always five in number, and reside in two eyes, two ears, twonostrils, the teguments of the tongue, and those of the body generally. Certain species,however, have the eyes obliterated. The nerves reach the medulla through perforations of the vertebras, or of the cra-nium : they all seem to unite with this medulla, which, after crossing its filaments,expands to form the various lobes of which the brain is composed, and terminates inthe two medullary arches {voutes) termed hemispheres, the volume of which corre-sponds to t
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Keywords: ., bookcentury1800, bookdecade1840, booksubjecta, booksubjectzoology
