Apeil 1-3, 1900.] 



SCIENCE 



569 



tension of Ethiopian climate and flora dur- 

 ing the Middle Tertiary. It is in a less 

 measure due to a migration from north to 

 south. Let us therefore clearly set forth 

 the hypothesis of the Ethiopian region, or 

 South Africa, as a great center of independ- 

 ent evolution and as the source of succes- 

 sive northward migrations of animals, some 

 of which ultimately reached even the ex- 

 tremity of South America — I refer to the 

 Mastodons. This hypothesis is clearly im- 

 plied if not stated by Blanford in 1876 in 

 his paper upon the African element in the 

 fauna of India. 



The first of these migrations we may 

 suppose brought in certain highly special- 

 ized ruminants of the upper Eocene, the 

 Anomalures or peculiar flying rodents of 

 Africa; with this invasion may have come 

 the Pangolins and Aard varks, and pos- 

 sibly certain Armadillos, Dasypodidce, if M. 

 Filhol's identification of Necrodasypus is cor- 

 rect. A second invasion of great distinct- 

 ness may be that which marks the begin- 

 ning of the Miocene when the Mastodons 

 and Dinotheres first appear in Europe, also 

 the earliest of the Antelopes. A third in- 

 vasion may be represented in the base of 

 the Pliocene by the increasing number of 

 Antelopes, the great girafies of the ^gean 

 plateau, and in the upper Pliocene by 

 the Hippopotami. With these forms came 

 the rhinoceroses with no incisor or cut- 

 ting teeth, similar to the smaller African 

 Rhinoceros, R. hicormis. . Another recently 

 discovered African immigrant upon the 

 Island of Samos in the ^gean plateau is 

 Pliohyrax or Leptodon, a very large member 

 of the Hyracoidea, probably aquatic in its 

 habits, indicating that this order (popularly 

 known as the conies) enjoyed an extensive 

 adaptive radiation in Tertiary times. 



It thus appears that the Proboscidia, 

 Hyracoidea, certain edentata, the Ante- 

 lopes, the Girafies, the Hippopotami, the 

 most specialized ruminants and among the 



rodents, the Anomalures, the Dormice, the 

 Jerboas and among Monkeys the Baboons 

 may have enjoyed their original adaptive 

 radiation in Africa — that they survived 

 after the glacial period, only in the Oriental 

 or Indo-Malayan region, and that this ac- 

 counts for the marked community of fauna 

 between this region and the Ethiopian as 

 observed by Blanford and Allen. 



Against the prevalent theory of Oriental 

 origin of these animals is : first, the fact 

 observed by Blanford and Lydekker in 

 the Bugti Beds (Sind) that the Oligocene 

 or lower Miocene fauna of the Orient is 

 markedly European in type ; second, that 

 if these animals had originated in Asia 

 some of them would have found their way 

 to North America ; third, the fact that all 

 these animals appear suddenly and without 

 any known ancestors in .older geological 

 formations. These are the main facts in 

 favor of the Ethiopian migration hypothesis. 



In the meantime the unification of the. 

 North American and Eurasiatic regions 

 was proceeding by intermigration. In the 

 lower Oligocene the giant pigs or elotheres, 

 the Tapirs and peculiar amphibious rhinoc- 

 eroses, known as Amynodons, found their 

 way from America to Europe, while Europe 

 supplied us with a few Authi-acotheres, 

 both Anthracotherium and Hyopotamus. 

 In the Miocene Europe sent us the true 

 Cats and we supplied Europe with the de- 

 structive sabre tooth tigers ; in the upper 

 Miocene Europe sent us our first deer and 

 cattle or Cervidw and Bovidce, also probably 

 the Mastodons en route from Africa. In the 

 Pliocene we supplied Europe with the rab- 

 bits and hares, and possibly with the rac- 

 coons, if the Panda belongs to this family. 

 In the Pleistocene the Camels wandered 

 into Asia from America, while the Bears 

 passed them e?i route to America. These 

 are a few instances out of many which are 

 already well known. 



On the other hand certain families had an 



