36 THE THEORIES OF EVOLUTION 



complex doctrine in which we must recognise two j 

 almost independent ideas: first, the fundamental the- 

 ory, the general theory of transmutation as formu- 

 lated by Lamarck; secondly, Darwin's original con- 

 tribution, an explanation of the process through 

 which the transformation of living beings is taking 

 place. It must be said, that although the idea of 

 descent had been formulated before Darwin, he con- 

 ceived it independently of Lamarck or any other 

 forerunner. We cannot help wondering why Dar- 

 win did not recognise in Lamarck's doctrine the 

 transmutation idea which serves as a basis for his own 



theory. 



Profound differences between his mentality and 

 that of the French zoologist may account for this lack 

 of perception on his part. No greater contrast-can 

 be imagined than the contrast between these two great 

 minds, Lamarck, who rushed to broad generalisations, 

 Darwin, who, always afraid of drawing hasty con- 

 clusions, painstakingly gathered data whose number 

 he never deemed large enough. 



Thus Darwin arrived at his theory in an absolutely 

 independent way, not by philosophical speculations, 

 but by the observation of a great many facts which 

 made his conclusions irresistibly convincing. 



His first -observations were made in the course of a 

 trip around the -world. In 1831, a youth of barely 

 twenty-two, Darwin sailed on the Beagle, a ship sent 



