GYMNASTICS.
If we compare the human F. with the feet of other mammals, we find that it presents certain peculiarities, all of which have reference to man's erect posture. The .chief peculiarities are-1. The greater relative size of the tarsal bones, as compared with the other bones of the F., and the more perfect formation of the plantar arch, which is higher and stronger than in any of the lower animals. Strength and elasticity are thus combined in the human F. in the highest degree. 2. The great toe is remarkable in man for its size and strength, and for the firm manner in which its metatarsal bone is joined to the other bones, so as to render it the main support to the foot. 3. If we compare the human F. with that of the gorilla, or any other anthropomorphous ape, we see that the toes are short and small in man in relation to the other parts of the F., while in the gorilla the toes form the greater part of the foot. Indeed, in this animal (and the same is the case in all the genera of apes and Monkeys) the organ in question is rather a hand than a foot, and hence the term quadrumanous, as applied to this class of animals. There is scarcely any plantar arch, and the weight of the body bears chiefly on the outer edge of the P.; the digits, are long and strong, and the inner one diverges so as to form a thumb rather than a great toe.
It remains to notice some of the most marked varieties of form which the bones of the F. present in mammals. Comparative anatomists give the same names to the bones which form the F, of other animals. As a general rule in all mammalia, the ecto-cunei form supports the third or middle of the five toes when they are all present, the meso cuneiform the second, and the cuboid the fourth and fifth. Bearing in mind this law, we see that the large bone in the horse, known as the cannon-bone, which is articu lated to the ecto-cuneiform, is the metatarsal of the third toe, to which are articulated the three phalanges of that toe, the last phalanx being expanded to form theloof. The small bone, popularly known as the splint-bone, and articulated to the mescr-cuneiform, is the rudimentary or stunted metatarsal] of the second toe; and the outer splint-bone, articulated to the cuboid, is the rudimentary metatarsal of the fourth toe: so that in the horse we have only one toe, the third, sufficiently developed to reach the ground, with mere traces of a second and fourth toe on either side.
In the F. of the ox, the _cuboid is relatively larger than in the horse, and is equal In size to the ecto-cuneifortn. The eannon-boilit'Airticulittes With both tlieSC tarsal bones, and hence answers to the metatarsal bones of both the third and fourth digits; it Is accordingly found to consist of two distinct bones in the fetus; and in the adult it is divided internally into two cavities, and its original separation is marked out by an external elongated ridge. At the lower end are two distinct joints for the phalanges of the third and fourth toes. While in the horse we had the rudiments of the upper parts of two toes (the second and fourth), in the ox we have the rudiments of the lower parts or phalanges of two toes (the second and fifth), forming the "spurious hoofs." In the rhinoceros there is one principal toe (the third), as in the horse, with the second and fourth toes in a less developed state; while in the hippopotamus there are two principal toes (the third and fourth), as in the ox: with the second and fifth toes not fully devel oped. In the elephant, there. is a fifth digit added, answering to our great toe, and articulating with an ento-cuneiform bone, so that in the F. of this animal we have all the bones occurring in the human foot.
Prof. Owen, to whose works we are indebted for these remarks, concludes from these and similar observations that the course of the simplification of the five-toed F. is, first, a diminution and removal of the innermost toe; next, of the outermost; then, of the second; and lastly, of the fourth; the third or middle' toe being the most constant and (in the lower animals) the most important of the five,