ACQUIRED CHARACTERS 89 



takes no active part in, nor is in any way affected by, 

 the vicissitudes through which the somatoplasm, or the 

 body itself, passes. The somatoplasm is thus merely 

 a carrier of the germplasm and unable to affect the 

 character of it any more than a rubber hot-water bag, 

 although capable of assuming a variety of shapes, can 

 affect the character of the water within it. 



In opposition to this view it is urged that every 

 organism is a physiological as well as a morphological 

 unity, and that cells entirely insulated within such a 

 unity would be a physiological miracle. 



There is abundant evidence that germ-cells, or 

 rather the hormones in the sexual organs producing the 

 germ-cells, do affect the somatoplasm under particular 

 conditions, as, for example, in cases of castration when 

 those somatic features called "secondary sexual char- 

 acters" undergo profound modification. 



Even here, however, it must be pointed out that it 

 is not the germ-cells themselves that are directly re- 

 sponsible for the modifications which occur, but rather 

 the hormones of the interstitial gonadal cells. A most 

 serious fly in the Weismannian ointment is due to the 

 results of certain recent experiments by Guyer and 

 Smith. 1 These ingenious experimenters injected into 

 fowls the freshly removed lenses of rabbits' eyes that 

 had been pulped up in Ringer's solution. The fowls 

 developed an "anti-body" which tended to dissolve 

 and disintegrate the rabbit lenses. When serum 

 from these fowls was in turn injected into pregnant 

 rabbits the mother was unaffected but nine out of sixty- 

 *Jour. Exp. Zool III, 1920. 



