210 7?. S. Lull— Evolution of the Elephant. 



latter is from Nebraska to southern Mexico along the 100° 

 meridian, although specimens in the Yale collection were found 

 as far east as Ohio and west to the California coast. We have 

 the authority of Lartet for the finding of a tooth of Elephas 

 in the Lower Pleistocene in Cayenne, French Guiana. From 

 the description of the "thick ridge plates 1 ' this specimen is 

 evidently that of E. imperator, probably a stray to the south- 

 ward before the conditions which later prohibited proboscidian 

 migration into South America arose. It is the only recorded 

 instance of a true elephant known to me south of the Mexi- 

 can plateau. The geographical range of E. columbi embraced 

 the whole southern part of the United States and the high- 

 lands of Mexico, including the area covered by E. imperator, 

 with the exception of the South American locality. 



Elephas primigenius phylum. 



(See Chart 4.) 



Elephas primigenius has been generally conceded to be of 

 Asiatic origin and a near relative of E. indicus. The charac- 

 ter of the teeth and the presence of hair in the young E. 

 indicus are certainly suggestive of relationship. The teeth are 

 also similar to those of JE. columbi and may represent a further 

 development of the latter type as readily as of E. indicus or 

 JS. antiquus. The presence of hair is an atavistic character 

 developed in E. primigenius to meet climatic conditions, and 

 we are by no means sure that E. columbi was naked, as this is 

 simply argued from its geographical distribution. The tusks 

 of E primigenius, however, are generally the immense spirally 

 coiled structures of E. columbi and E imperator, though 

 short-tusked specimens do occur, presumably young individu- 

 als. In E. itidicus th,e tusks are greatly reduced, being absent 

 in the female, often in the male, and are evidently degenerate. 



Elephas columbi molars grade into those of E primigenius, 

 and there is preserved in the Yale museum a line jaw, the 

 characters of which are clearly those of E. primigenius, 

 while the teeth are those of E. columbi. In fact, E. columbi 

 is often regarded merely as a southern variety of the Siberian 

 mammoth. It seems, however, as though the reverse of this 

 statement might be true, looking upon E. primigenius, which 

 is the more specialized form, as the latest mutation of the 

 imperator-columbi phylum, originating in North America and 

 becoming circumpolar in its distribution, invading Siberia 

 from the American northwest. One tooth has been found on 

 Long Island in the eastern part of Hudson bay, transitional in 

 character between the mammoth and Elephas columbi. Lucas 



