48 LAND MAMMALS IN THE WESTERN HEMISPHERE 



while the external characters of skin, hair and colouration are 

 largely conjectural, but not altogether imaginary. It cannot 

 be doubted that among the extinct mammals were many which, 

 owing to some uncommon growth of subcutaneous fat, or some 

 unusual local development of hair, were much more curious and 

 bizarre in appearance than we can venture to represent them. 

 If, for example, the Camel, the Horse, the Lion and the Right 

 Whale were extinct and known only from their skeletons, 

 such restorations as we could make of them would assuredly 

 go astray in some particulars. The Camel would be pictured 

 without his hump, for there is nothing in the skeleton to suggest 

 it ; the forelock, mane and characteristic tail of the Horse and 

 the Lion's mane would certainly not be recognized ; while the 

 immense development of blubber in the head of the Whale 

 gives to it a very different appearance from that which the 

 skull would seem to indicate. Such cases are, however, ex- 

 ceptional and restorations made by competent hands from 

 complete skeletons probably give a fair notion of the appearance 

 of those animals when alive. 



It will thus be sufficiently plain that the work of restora- 

 tion is beset with difficulties, but that there is no good ground 

 for the uncritical scepticism which summarily rejects the re- 

 sults as being purely fanciful, or for the equally uncritical 

 credulity which unhesitatingly accepts them as fully and in- 

 contestably accurate. It is altogether likely that one of the 

 main sources of error consists in making the extinct animal 

 too closely resemble some existing species which is selected as 

 a model. 



Too much space has perhaps been devoted to the problem 

 of restoring the external form of these extinct mammals, 

 a problem which, after all, is of distinctly subordinate impor- 

 tance. The most valuable results which may be gained 

 from a study of these fossil mammals are the answers which 

 they afford to the great questions of relationship, classification 

 and genetic descient, and the light which they throw upon the 



