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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 edition. Excerpt:...respectively as the astragalus and calcaneum, are greatly elongated. This state of affairs seems to be correlated with the leaping of the amphibian, for a similar modification is to be found in the jumping Jerboa. The distal rows of tarsal bones are cartilaginous, and there are five complete toes, with a rudiment of a sixth, in the form of a small bone known as the calcar. The hind limb of the Bird differs in several important particulars from that of the frog. The femur; to begin with, is much shorter than the tibia; the fibula is rudimentary, and does not reach far down the tibia. This bone, the tibia, is followed by a long bone, with which the four toes articulate. Thus the tarsus appears to be wanting. As a matter of fact, a study of the immature chick shows that what is apparently the tibia, is really the tibia plus the proximal elements of the tarsus; and what appears to be the metatarsus is really the three-fused metatarsals, phis the distal elements of the tarsus. Thus the ankle-joint is not, as it is in the frog and in the rabbit, between the end of the tibia and the tarsus, but in the middle of the tarsus. Hence it is more correct to apply the terms "tibio-tarsus" and "tarso-metatarsus " to the long bones in question. The metatarsal part of the tarso-metatarsus contains, fused together, only three out of the four metatarsals, those corresponding to the three long toes. The short hallux (or great toe) has a small metatarsal, loosely attached to the end of the tarso-metatarsus. The bird is bipedal in its progression, as is the frog to all intents. But the required elongation of the limb is brought about in the bird by the elongation of the tibia and the metatarsus, not of the astragalus and calcaneum. In the Rabbit the...