MENDELISM 



CHAP. 



plants, but only by some of the ovules. Though 

 the nature of doubleness in stocks is not yet clearly 

 understood, the facts discovered by Miss Saunders 

 suggest strongly that the ovules and pollen grains 

 of the same plant may differ in their transmitting 

 properties, probably owing to some process of 

 segregation in the growing plant which leads to an 

 unequal distribution of some or other factors to 

 the cells which give rise to the ovules as compared 



Single 



Single 



Double 



Pollen of 

 pure single 



X Ovule 



Pollen 



Single Single 



Single Single Double 

 Single Single Double 



Ovule of 

 x pure single 



Single 



Single Double 



Single Double 



with those from which the pollen grains eventually 

 spring. Whether this may turn out to be the true 

 account or not, the possibility must not be over- 

 looked in future work. 



From all this it is clear enough that there is 

 much to be done before the problem of sex is solved 

 even so far as the biologist can ever expect to solve 

 it. The possibilities are many, and many a fresh 

 set of facts is needed before we can hope to decide 

 among them. Yet the occasional glimpses of clear- 

 cut and orderly phenomena, which Mendelian 



