2 THE DESCENT OF THE PEIMATES 



the plan on which living things are built, and of 

 the way in which they work. 



In order to classify the collected facts methodi- 

 cally, he looks out for some system or other 

 according to which a satisfactory arrangement of 

 the varied forms of life may be made. More 

 than a hundred years ago Linnaeus produced the 

 first really all-embracing arrangement, in his 

 " Systema Naturae." 



Up to 1859, however, all this seemed more or 

 less artificial ; and although a difference was un- 

 doubtedly made between what was called an 

 artificial and what was looked upon as a natural 

 system, still the latter did not commend itself to 

 naturalists as the expression of some great law 

 wdiich is even now at work throughout nature, 

 but more as a cupboard in which the facts 

 happen to fit in together nicely ; whereas in what 

 is called an artificial system they are, so to say, 

 heaped together according to size, color, or 

 number. 



Since 1859 a fundamental change has come 

 over natural history. Thanks to tlie labors of 

 Charles Darwin, evolution is now as universally 

 acknowledged as is gravitation, and we have 

 come to look upon all systems of classification as 

 preliminary attempts definitely to establish that 



