142 DARWINISM TO-DAY. 



etc., would be extremely likely to be fallacious. If, however, 

 we keep in mind the facts that ( i ) the whole and not merely 

 a part of the organism is selected, and that, therefore, 

 each variation does not require to be of the same value as if 

 selection depended on it alone; (2) specialisations are 

 largely quantitative, between man at one extreme of de- 

 velopment and a simple unicellular organism at the other, 

 the difference, though very great, is mainly due to the fact 

 that man is a huge multicellular colony ; this difficulty will be 

 much simplified. To estimate the quantitative difference it is 

 necessary to endeavour to determine the specialisation of an 

 individual cell in one of those collective specialisations or 

 organs : the difference between a cell in, for instance, the 

 cerebral cortex of man and the character of an amoeba is no 

 doubt great, but the amceba reacts to stimuli, though in a 

 less specialised form, just as the cortex cell does ; in the same 

 way the reaction to light in the mammalian eye is not a new 

 development it has its beginnings in the preference for 

 light or darkness shown by many unicellular organisms. 

 These two points, that selection is organismal and that 

 specialisations are as, or more, largely quantitative than 

 qualitative, weaken if they do not abolish all those diffi- 

 culties to natural selection that are founded on this objec- 

 tion, and it is further necessary to recollect that no specialisa- 

 tion has yet been found which has not a primitive counter- 

 part in the earliest known forms of life." 



With regard to the objection that because natural selec- 

 tion working with fluctuating Darwinian variations is 

 working only with linear or quantitative varia- 

 tions and therefore cannot produce many- 

 selection cannot branched descent (which is certainly the kind 

 of descent that exists) but only straight-line or 



and discontinuity mono-typic descent, it is obvious that the Dar- 

 in series. . . . 



wmian answer to this is partly that of the 



answer to the objection discussed in the last paragraph. In 



