The following answers may be given to these objections, or arguments: 1. It is just as reasonable to suppose that man is affected, as well as the animals, by climate, food, or peculiar condition. It is well known that animals have undergone more or less change by their situation or position. Elephants and rhinoceroses are almost hairless. As certain extinct species, which formerly lived under an arctic climate, were covered with hair or long wool, it would appear that the present species of both genera had lost their hairy covering by exposure to heat. This is confirmed by the fact that the elephants of the elevated and cool districts of India are more hairy than those on the lowlands.[112] A wonderful change is wrought by the influence of climate on turkeys. In India "it is much degenerated in size, utterly incapable of rising on the wing, of a black color, and with long pendulous appendages over the beak, enormously developed." "In the English climate an individual Porto Santo rabbit recovered the proper color of its fur in less than four years."[113] Observers are convinced that a damp climate affects the growth of the hair of cattle. The mountain-breeds always differ from the lowland breeds; in a mountainous country the hind limbs would be affected from exercising them more, which would also affect the pelvis, and, then, from the law of homologous variation, the front limbs and head would probably be affected.[114] One of the most marked distinctions in the races of man is that the skull in some is elongated or dolichocephalic, and in others rounded or brachycephalic. Mr. Darwin has observed that a change takes place in the skulls of domestic rabbits; they become elongated, while those of the wild rabbit are rounded. He took two skulls of nearly equal breadth, the one from a wild and the other from a large domestic rabbit, the former was only 3.15, and the latter 4.3 inches in length. Welcker has observed "that short men incline more to brachycephaly and tall men to dolichocephaly; and tall men may be compared with the larger and longer-bodied rabbits, all of which have elongated skulls."[115] The argument from language is of great weight, especially in considering the differences in color. Professor Max Müller has stated this clearly: "There was a time when the ancestors of the Celts, the Germans, the Slavonians, the Greeks and Italians, the Persians and Hindus, were living together beneath the same roof." "The evidence of language is irrefragable, and it is the only evidence worth listening to with regard to ante-historical periods. It would have been next to impossible to discover any traces of relationship between the swarthy natives of India and their conquerors, whether Alexander or Clive, but for the testimony borne by language."[116] When the great lapse of ages is taken into consideration, since man originated, it will be seen that sufficient time is given to produce the white, black, yellow, red, and brown varieties of man.