THE THEORY OF SEX 595 



is carried by the latter. Further, it was proved that [FF] is 

 inherited purely maternally and is, therefore, contained in every 

 egg, presumably in its cytoplasm. 



11 



In using this modified Mendelian explanation we must keep 

 in mind what its real meaning is. When we use Mendelian 

 formulae we are expressing the fact that the unknown things, 

 for which the Mendelian symbols stand, behave as units in in- 

 heritance and are distributed among the offspring of an or- 

 ganism unchanged and according to definite laws. When we 

 talk about sex-factors, therefore, we only express the view that 

 the sexual differences are due to different combinations of things 

 of the same type as those which stand for genetic differences of 

 other kinds, things which we symbolize as unit-factors. The 

 mechanism of distribution of these things can again be symbol- 

 ized by an imaginary system of segregation, coiupling, and re- 

 pulsion. Or, we understand it as the consequence of the visible 

 distribution of definite chromosomes, thus substituting reality 

 for symbolism. But this applies, of course, only to the mech- 

 anism of distribution of the symbolic factors and says nothing 

 about their quality. 



We are now forced to ascribe one definite quality to these sym- 

 bolic factors in order to be able to explain the otherwise inex- 

 plicable results of our experiments. We recognized and ex- 

 pressed, from the very beginning of our work, the view that 

 these factors have an effect of a definite quantity. And this 

 must certainly be regarded as a first step toward replacing a 

 symboUstic representation — and the conception of potency is 

 again a symbolistic attribute of the symbolic factor, but one with 

 the important quality of quantitative action — by a sound 

 physiological conception. And now the question arises whether 

 the results of our experiments do not enable us to replace our 

 symbolistic interpretation by a physiological one, to give a real 

 meaning to the words sex-factor, potency, intersexuality, the 

 value of e, etc. The purpose of this paper is to show that we 

 have now reached this point. 



