SCOPE OF GENETICS 15 



heredity. For we find definite experimental 

 proof in nearly all the cases which have been 

 examined, that the germ-cells formed by such 

 individuals do either contain or not contain a 

 representation of the ingredient, just as the 

 original gametes did or did not contain it. 



If both parent-gametes brought a certain 

 quality in, then all the daughter gametes 

 have it; if neither brought it in, then none 

 of the daughter gametes have it. If it came 

 in from one side and not from the other, then 

 on an average in half the resulting gametes 

 it will be present and from half it will be 

 absent. This last phenomenon, which is 

 called segregation, constitutes the essence of 

 Mendel's discovery. 



So recurring to the simile of the man as 

 made by the mixing of tinctures, the process 

 of redistribution of his characters among the 

 germ-cells may be represented as a sorting 



