172 UNIVERSITY OF COLORADO STUDIES 



Mechanism teaches that a lot of species have evolved accidentally. 

 Well, if this were so in a sense, how is it we find such striking similari- 

 ties ? Why have so many species eyes, and other organs, functioning 

 in much the same way, if it is all the chance of matter and blind forces ? 

 But if the original impulse had in a sense a common aim, then these 

 highly divergent species might really be expected to show striking 

 similarities. 



None of the Current Explanations of Evolution Sound 



From page 55 to page 85 Bergson endeavors to make good his 

 attacks on the current views of evolution. He begins by seeking an 

 example of development which will be fair and typical and which will 

 stand as it were for the whole process. He rejects sex as of uncertain 

 function, and finally settles upon the "eye." He proceeds to examine 

 the accounts of the evolution of the eye from its earliest form as given 

 by a neo-Darwinist, by DeVries, by Eimer and by the neo- 

 Lamarckians. His final conclusion is that the first three, being purely 

 mechanical, are most unsatisfactory, and that Lamarckism has some, 

 but not much, idea of his own view, which is psychological. 



The finalists, he says, talk a great deal about the miraculous 

 structure of the eye : but it functions at first as a mere pigment-spot, 

 which may really be accidental. The evolutionists step in to explain 

 how this spot develops until we get the eye of a man or of an eagle. 



First come the Darwinists with their "insensible variations," then 

 DeVries with his "sudden mutations." Both favor the purely acci- 

 dental hypothesis. Next comes Eimer with his idea of a variation 

 controlled directly along a definite line under the immediate influence 

 of external conditions. 



According to Darwinians, the eye changed very, very slowly, and 

 whatever was good in this slow and imperceptible change was retained ; 

 the rest was eliminated. 



According to DeVries, the eye would change all at once by the 

 simultaneous appearance of several new characters. 



Bergson says as he sees the problem both views may be partly 

 true. But if these variations are accidents, neither view tells the 



