224 



BEAN. 



Environment begins its action wlien cell division commences, the en- 

 vironment of each cell becoming difJerent from that of its predecessor. 

 In this way the side chains become changed and heredity is aifected 

 (fig. 5). 



rirat Par 



Oocyte 



O OCyte 



n.R. 



Fig. 5. — A single germ cell after fusion with another may be acted upon by environment, 

 the struggle of parts, use and disuse, physical activity, organic selection, natural 

 selection, isolation, or any other influence, so that after many generations have passed 

 each individual developed from the original germ cell will have become differentiated 

 and specialized. It the influences have been opposite in nature on two groups of 

 individuals in different localities, extreme variations in opposite directions may have 

 taken place. When these variations are crossed, there is an exhibition of Mendel's laws 

 as illustrated in the figure, for a period of time, with inbreeding, but finally there is 

 fusion more or less complete. At some time in the course of fusion there are three 

 types, the two original ones and a blend of the two. The ultimate result may be 

 complete fusion with the formation of a perfect blend. 



