12-4 ORGANIC EVOLUTION — THE FACTORS 



tissues of the parent are constituted: units composed, 

 as wc must assume, of vaviously-arranged molecules of 

 protein. So that the big tiling may jjass, and the little 

 thing- may pass, but the intermediate thing may not 

 pass " (p. 32), 



It is hardly necessary to argue the matter : of course 

 if the gemmules or physiological units exist they must 

 be able to enter the germ cells as do food molecules, as 

 do microbes, and as do spermatozoa. This is not the 

 thing denied. It is the very existence of the elements 

 which cause the germ cells to proliferate into organ- 

 isms with the acquired variations of the parent that is 

 denied. The existence of gemmules or physiological 

 units is assumed, that the transmission of acquired vari- 

 ations may be accounted for. There is no other evidence 

 of their existence, except such as is furnished by the sup- 

 posed transmission of such variations. But as I have 

 just shown, acquired variations as regards higher animal 

 organisms, to which alone Mr. Spencer directs his atten- 

 tion, are apparently not transmitted, but that only the 

 power to vary in response to stimulation is transmitted; 

 and variations in this power cannot be acquired in the 

 sense that is increased by stimulation, by use, and de- 

 creased by the lack of it, by disuse. Therefore neither 

 acquired variations nor an acquired power of varying 

 can be transmitted ; and therefore since there is nothing 

 to show that gemmules or physiological units exist, it is 

 vain until this is proved to discuss the possibility of their 

 entrance into the germ cells. That is not, as I say, the 

 point at issue. 



But Mr. Spencer has another string to his bow. Ac- 

 cording to him, and in this he follows Mr. Adam Sedg- 

 wick, a so-called multicellular organism is not really a 

 multicellular organism, but " a continuous mass of vacuo- 

 lated protoplasm," a sort of gigantic unicellular organism. 



