This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1855 edition. Excerpt: ... CHAPTER III. THE COMPARATIVE ANATOMY OF THE HAND. In this enquiry, we have before us what in the strictest sense of the word is a system. All the individuals of the extensive division of the animal kingdom which we have to review, possess a cranium for the protection of- the brain, --a heart, implying a peculiar circulation, --five distinguishable organs of sense; but the grand peculiarity, whence the term vertebrata is derived, is to be found in the spine; that chain of bones which connects the head and body, and, like a keel, serves as a foundation for the ribs; or as the basis of that fabric which is for respiration. I have said, that we are to confine ourselves to a portion only of this combined structure; to separate and examine the anterior extremity, and to observe the adaptation of its parts, through the whole range of these animals. We shall view it as it exists in man, and in the higher division of animals which give suck, the mammalia--in those which propagate by eggs, the oviparous animals, --birds, reptiles, amphibia, and fishes; and we shall find the bones which are identified by distinct features, adjusted to various purposes, in all the series, from the arm to the fin. We shall recognize them in the mole, formed into a powerful apparatus for digging, by which the animal soon covers itself, and burrows its way under ground. In the wing of the eagle we shall count every bone adapted to a new element, and as powerful to rise in the air, as the fin of the salmon is to strike through the water. The solid hoof of the horse, the cleft foot of the ruminant, the retractile claw of the feline tribe, the long folding nails of the sloth, are among the many changes that are found in-the adjustment of the chain of bones which, in man, ...