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Fig. 382.—Skeletons of Feet of Mammals.

P, horse; D, dolphin; E, elephant; A, monkey; T, tiger; O, aurochs; F, sloth; M, mole.

Question: Explain how each is adapted to its specialized function.

According to the usual rule, they tended to increase faster than the food supply, and there were continual contests for food. Those whose claws and teeth were sharper drove the others from the food, or preyed upon them. Thus the specialization into the bold flesh eating beasts of prey and the timid vegetable feeders began. Which of the flesh eaters has already been studied at length? The insectivora escaped their enemies and found food by learning to burrow or fly. The rodents accomplished the same result either by acquiring great agility in climbing, or by living in holes, or by running. The proboscidians acquired enormous size and strength. The hoofed animals found safety in flight.

Fig. 383.—Feet of the ancestors of the horse.