96 THE TRIUMPH OF THE MAMMALS 



story still in circulation that a distinguished man of 

 science once said that, if you gave him a single bone 

 of some dead animal, he could build up the whole 

 body. Scientific men are far more modest. A few 

 years ago they found the better part of a battered 

 himaan skiill in Sussex, but they are disputing to this 

 day how the missing parts of that skull ought to be 

 filled in. 



Now, of the early mammals we have only a few 

 small bones in the rocks, and they would not tell us 

 much by themselves. But you remember how we 

 were able to describe, in the fourth chapter, the fishes 

 which ten millions of years ago left the water and 

 began to live on land. Remnants of that primitive 

 family, the lung-fishes, still survive in nature. 

 Animals of this kind are often called "living fossils." 

 They help us even more than fossils do. No speci- 

 mens of the earliest birds have survived in nature, 

 and we should know very little about them if we had 

 not been so lucky as to find the two fossil birds in 

 Bavaria. But with the mammals it is quite different. 

 Nature has preserved specimens of them alive for us. 



We are fond of saying that nature "does" this or 

 the other. Of course, it is literally true, as all the 

 forces and causes or agencies that we know belong to 

 nature. But even children ought to be warned against 

 the practice of thinking that "nature" has intentions. 

 Take, for instance, this preservation of the early 

 mammals all through several millions of years. It 



