The evolution of man: a popular exposition of the principal points of human ontogeny and phylogene . ig (III.) and the Tapir (V.)this digit has entirely disappeared. So, too, in the Rumi-nants (, the Ox, Fig. IV.) the second and fifth digits arealso aborted, and only the third etnd fourth are well deve- 3o6 THE EVOLUTION OF MAN. loped. Finally, in the Horse, only one digit, the third, isperfectly developed (Fig. VI., 3). And yet all these diversefore-feet, as also the hand of the Ape (Fig. 271) and thehuman hand (Fig. 272), have originated from the samecommon five-fingered parent-form. Thi
The evolution of man: a popular exposition of the principal points of human ontogeny and phylogene . ig (III.) and the Tapir (V.)this digit has entirely disappeared. So, too, in the Rumi-nants (, the Ox, Fig. IV.) the second and fifth digits arealso aborted, and only the third etnd fourth are well deve- 3o6 THE EVOLUTION OF MAN. loped. Finally, in the Horse, only one digit, the third, isperfectly developed (Fig. VI., 3). And yet all these diversefore-feet, as also the hand of the Ape (Fig. 271) and thehuman hand (Fig. 272), have originated from the samecommon five-fingered parent-form. This is proved, not onlyby the rudiments of the aborted digits, but also by thehomologous disposition of the wrist-bones (Fig. 273, a-p).(Vide supra, p. 124.) The same story is also told by the germ-history of theKmbs, which is originally identical, not only in all Mammals,but in all Vertebrates. However different the limbs of thevarious Skulled Animals (Graniota) afterwards appear intheir fully developed state, they nevertheless all originatefrom the same simple rudiment. (C£ Plates VI. and VII.,. 4^ 5 Fig. 273.—Skeleton of hand or fore-foot of six Mammals. I. Man; ; III. Pig; IV. Ox; V. Tapir; VI. Horse, r, Radius; u, ulna;a, scaphoid; &, semi-lunar; c, triqnetrum (cuneiform); d, trapezium; Cftrapezoid ; /, capitatum (unciform process) ; g, hamatum (unciform bone);jt), pisiform; 1, thumb; 2, digit; 3, middle finger; 4, ring finger; 5, littlefinger. (After Gegenbaur.) ORIGIN OF THE LIMBS. 307 vol. i. p. 362; /, fore-leg, b, hind-leg.) In all, the first rudi-ment of each limb in the embryo is a simple wart, or smallknob, which grows from the side of the body between thedorsal and ventral sides (Figs. 119 and 120, vol. i. pp. 357, 359;136 and 137, pp. 381, 382). The cells composing these loiobsbelong to the skin-fibrous layer. The outer surface is coatedb} the horn-plate, which is rather thicker at the apex ofthe protuberance (Plate lY. Fig. 5, x). The two anteriorprotuber
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