488 



GENETICS IN RELATION TO AGRICULTURE 



the transplanted tissue failed to function. Accordingly as the matter 

 stands at present with regard to the relation of soma and stirp it has not 

 been demonstrated that any mechanism for the direct influence of the 



FIG. 193. The offspring of the pair of albinos shown in Fig. 192. 4 and 5, young 

 black females of the first litter; 6, young black male of the second litter; 7, 8, 9, skins of the 

 black males found in utero after the death of No. 24. (After Castle and Phillips.) 



germ cells by the body exists; and such critical experimental evidence 

 as has been obtained indicates that probably no such mechanism does 

 exist. 



The Isolation of the Germ-plasm. Many biologists see in the con- 

 tinuity of the germ-plasm and in its apparent isolation from the soma an 



