CHAPTER XIV A . 



RECENT CRITICISMS AND HYPOTHESES. 



174a. SINCE the first edition of this work was published, 

 and more especially since the death of Mr. Darwin, an active 

 discussion of the Evolution hypothesis has led to some sig- 

 nificant results. 



That organic evolution has been going on from the dawn 

 of life down to the present time, is now a belief almost 

 universally accepted by zoologists and botanists " almost 

 universally," I say, because the surviving influence of Cuvier 

 prevents acceptance of it by some of them in France. Omit- 

 ting the ideas of these, all biological interpretations, specu- 

 lations, and investigations, tacitly assume that organisms 

 of every kind in every era and in every region have come 

 into existence by the process of descent with modifica- 

 tion. 



But while concerning the fact of evolution there is agree- 

 ment, concerning its causes there is disagreement. The 

 ideas of naturalists have, in this respect, undergone a dif- 

 ferentiation increasingly pronounced ; which has ended in 

 the production of two diametrically opposed beliefs. The 

 cause which Mr. Darwin first made conspicuous has come to 

 be regarded by some as the sole cause; while, on the part of 

 others there has been a growing recognition of the cause 

 which he at first disregarded but afterwards admitted. 

 Prof. Weismann and his supporters contend that natural 

 selection suffices to explain everything. Contrariwise, among 



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