154 DARWINISM TO-DAY. 



favourable variations, while another may survive in virtue 

 of a single valuable one, but in each case it would be the 

 whole value of that organism which determined its survival. 

 This fact is continually disregarded by opponents of the 

 neo-Darwinian position, yet this selection of the organism 

 as a whole is the fundamental postulate from which the 

 theory of selection starts. Thus it is not uncommon to 

 read criticisms bearing on the early development of some 

 organ, in which the inadequacy of selection is supposed to 

 be proved by the writer demonstrating, or believing he has 

 demonstrated, the fact that the particular variation in ques- 

 tion must have been too small to be by itself of selection 

 value. In many cases the particular variation would, no 

 doubt, if taken alone be, as the objector asserts, too unim- 

 portant to be selected, but as it is the whole organism that 

 is selected, it is not logical to make an artificial separation 

 and study the development of one organ or structure irre- 

 spective of the other organs with which it is in nature asso- 

 ciated. Every organ in its evolution must be considered in 

 relation to the whole of the particular organism in which 

 that particular stage of development of that organ is found. 

 Starting, therefore, with this fact that the net value of 

 adaptability of the whole organism to its environment must 

 be the basis which determines selection or elimination, it 

 will follow that certain lines of development will result from 

 the application of this criterion. In a series of organisms 

 placed under new conditions, elimination will proceed along 

 lines essential to bring about a proper adjustment to the 

 new conditions. If the offspring of these adjusted organ- 

 isms merely repeated in their generation the characters of 

 the exterminated as well as of the surviving organisms, 

 that temporary adjustment would be permanent as long as 

 the conditions were unchanged. But since the offspring are 

 produced only by the surviving organisms, selection is con- 

 tinually raised to higher and higher planes of adaptation, 





