MENDELIAN SEGREGATION 



corresponding unit derived from the mother. These 

 units will henceforth be spoken of as factors; the 

 two factors of a pair are called allelomorphs of each 



l\ 



/\ 



A 



d 



A 



I 



i k 



Fig. 1. — In the upper line, four stages in the division of the egg (or 

 of a body cell) are represented. Every chronio.soine divides when the 

 cell divides. In the lower line the "reduction division" of a germ cell, 

 after the chromosomes have united in pairs, is represented. The mem- 

 bers of each of the four pairs of chromosomes separate from each other at 

 this division. 



other. Their separation in the germ cells is called 

 segregation. 



The j)ossibility of explaining Mendelian phenomena 



