172 Charles Danvin. 



life, something to the crossing of already existing 

 forms, and much to use and disuse — that is, to the 

 effects of habit. To this latter agency he seems to 

 attribute all the beautiful adaptations in nature — ^ 



(such as the long neck of the giraffe for browsing on 

 the branches of trees." Lamarck's theory may be 

 expressed briefly : he avowed that all life, including 

 man , had descended by various modifications from 

 one or more primordial forms, and he believed that 

 the various animals had to a greater or less extent 

 been developed by their habits, their efforts to live, 

 and the conditions which surrounded them. 



No writer of the day produced the effect of La- 

 marck. His " Philosophie Zoologique " influenced 

 the scientific sentiment of all Europe, and the writ- 

 ings of the men of his time and ever since are tinc- 

 tured with his philosophy. 



In the year 1844 renewed interest was created in 

 the subject by the appearance of a work entitled 

 " Vestiges of Creation," supposed to be written by 

 Robert Chambers. Humboldt now affirmed his be- 

 lief that species are not immutable, and following 

 came Owen, Asa Gray, Herbert Spencer, Youmans, 

 and many more who had thought upon evolution 

 and believed in it in some form. 



It will be seen, then, that evolution as a theory is 

 not of recent origin, but was discussed /r£> and con 

 until the time described in a previous chapter, when 

 \ [Charles Darwin and Alfred Wallace came out simuW 

 jtaneously with their views on the subject ; thenj 

 V Darwinism was born, and in it we find our hero's 

 /explanation of the method of evolution. 



