MAMMALIAN DAWN. 83 



and the peculiar, leopard-like markings, we have altogether 

 an animal of a very unique type. It is probable that the 

 giraffes of Africa are immigrants from the south of Europe. 

 Further tracing leads us to an animal of the early Pliocene 

 inhabiting Southern Europe and Asia, with a type of struct- 

 ure very much like that of the giraffe and associated with 

 genera which seem to have connected it with the primitive 

 Hollow-horned Ruminants. The only known remains of this 

 animal are very fragmentary and do not include the top of 

 the skull, therefore it is not yet certain whether it had the 

 same character of horns as the existing giraffe. Its equally 

 long neck and limbs, with the similarity of the teeth, how- 

 ever, clearly define its affinities to the giraffe family. 



Among the mammalian remains recovered from the Mio- 

 cene strata of Central Europe and India are those of the Dino- 

 therium, a huge animal with a remarkable downward curva- 

 ture of the end of the lower jaw, from which projected two 

 long tusk-like teeth directed downward and backward. From 

 the points of these teeth to the top of the cranium was five 

 feet, and the skull, which measured three feet in length, gave 

 evidence of having had attached to it an elephant-like pro- 

 boscis. This animal was among the earliest of the Probos- 

 cideans, but with its completely lost upper incisors and the 

 peculiar conversion of the lower ones into down-curved tusks, 

 it cannot be regarded as an actual link between the elephant 

 and its primitive ancestors ; the mastodons occur in almost 

 the same geological horizon with the dinotheres, and from this 

 on DhioiJierinw, Mastodon and Elephas successively exhibit 

 the change of the incisors into the characteristic elephantine 

 tusks, with the acquirement of the prehensile proboscis. In 

 relation to the tusk development of our modern elephants, it 

 is interesting to note that some of the Miocene mastodons 

 exhibit an upper and a lower pair of constantly growing inci- 

 sors, while in the Pliocene most of the species have so far 

 advanced as to be entirely destitute of lower incisors, and the 

 upper ones are tusk-like. In the elephant, as is well known. 



