The common frog . Fig. 57.—Elongated tarsus of Leaiuroids. Left-hand figure, tarsus of Cheiyogaleusright-hand figure, tarsus of Tarsius. A, calcaneum B. cuboides, C, navi-culare. analogous structure. None of the lowest mammals, nomarsupial, no rodent, no insectivorous or carnivorousbeast, no hoofed mammal, presents us with anythingof the kind. Nevertheless, at almost the other end ofthe series, in the very highest order, that to which 92 THE COMMON FROG. [chap. man himself belongs, we actually find a similardevelopment. Amongst the very peculiar beasts v/hich inhabit theisland of Madagascar, t
The common frog . Fig. 57.—Elongated tarsus of Leaiuroids. Left-hand figure, tarsus of Cheiyogaleusright-hand figure, tarsus of Tarsius. A, calcaneum B. cuboides, C, navi-culare. analogous structure. None of the lowest mammals, nomarsupial, no rodent, no insectivorous or carnivorousbeast, no hoofed mammal, presents us with anythingof the kind. Nevertheless, at almost the other end ofthe series, in the very highest order, that to which 92 THE COMMON FROG. [chap. man himself belongs, we actually find a similardevelopment. Amongst the very peculiar beasts v/hich inhabit theisland of Madagascar, there are certain small creatures,. Fig. 58.—The Maholi Gabgo. Half-Apes, belonging to the genus CJieirogalais, inwhich two of the ankle-bones are elongated in amanner similar to that of the frog. The samecharacter is more marked in an African genus of half- VI.] THE COMMON FROG. 93 apes {Galago), and still more so in a third half-ape{Tarsms), from the island of Banca. Now it isabsolutely impossible to believe that a special genetic 1 Raffinity connects together by a peculiarly common « »descent, Half-Apes and Frogs 1 We are then drivento the conclusion that we have here again a strikingsimilarity of structure in two instances which are quiteindependent in their origin. That the power of rapid and prolonged jumping does not carry with it as a necessary consequence theelongation of ankle-bones, is demonstrated by thefact that in other animals which, to say the very least,jump no less than do these half-apes—as for examplein the kangaroos, jumping shrews, and jerboas—it isnot bones of the ankle but bones of the fo
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