174 STUDIES IN LIFE AND SENSE. 



by the modification of the old. The bears and deer are unknown 

 in Africa, on the contrary, since they were later comers in European 

 territory, and because they found migration a difficult or impossible 

 task. The fauna which Europe then gave to Ethiopia was killed 

 off in the former by the climatal changes which succeeded these 

 Miocene times, and which left the region to be peopled after the 

 glacial cold, by the hardier forms which we now call our representa- 

 tive animals. Similarly, India as the Oriental province possessed 

 when detached from Asia its own lower Edentates, and its lemurs ; 

 but when it became united with the Asiatic continent, it received 

 from the north, like Africa, its new complement of animals its 

 monkeys, tigers, elephants, and other forms these animals arising 

 in the ancient Palaearctic land, whence, as we have seen, the earlier 

 marsupials themselves migrated to people the other quarters of the 

 globe. 



The history of the New World is equally instructive, both as 

 regards the proofs it supplies of the permanence of the continents, 

 along with the evidences of the same laws of dispersal and migration 

 of life which the consideration of the Old World areas affords. The 

 first fact of importance in the scientific history of the New World 

 areas consists in the knowledge that in the Post-Pliocene times the 

 life of the Nearctic region approached very closely to that of the 

 Palsearctic province. In the Post-Pliocene formations of America, 

 we find the fossil remains of numerous carnivora, horses, camels, 

 bisons, and elephants. Of the living elephants, as we have seen, the 

 existing New World knows nothing. The horses were reintroduced 

 by man ; whilst the buffalo certainly represents the bisons, and the 

 llamas similarly represent the camels. Before the Post-Pliocene 

 time, geology reveals that America possessed rhinoceroses, special 

 forms of ruminants, and a porcupine decidedly of Old World type. 

 In the still earlier Miocene period, North America had its lemurs 

 now limited to India, Africa, and Madagascar many carnivora, 

 camels, deer, and tapirs. Earlier still, that is, in the Eocene period, 

 there lived in North America animals unlike any forms now existent. 

 There were the Tillodonts and Dinoceratidae of Professor Marsh, 

 which appear to have united in themselves the characters of several 

 distinct orders of quadrupeds. There is thus every reason to believe 

 that in the Post-Pliocene period, at least, and in earlier times like- 

 wise, there was free land communication between the Palaearctic 

 and Nearctic areas. So that it requires no stretch of hypothesis to 

 assume that the horses, camels, elephants, and other quadrupeds of 

 America proved to be near allies of European fossil forms must 

 have freely intermingled with those of Europe. That Europe, or, 

 more properly, the Palsearctic region, must have been the original 

 source whence the Nearctic land obtained its mastodons, porcupines, 



