Heredity - 501 



-^ 



Fig. 26-23. Cross of red- 

 eyed female and white-eyed 

 male; Fj inbred. (Adapted 

 from Morgan.) 



dfo 



d© 



perpetuate its favorable combination of the generations. Propagation by seed, even 



qualities. Opportunity is not afforded for the when artificial self-pollination is practiced, 



loss of advantageous genes, or the gain of usually gives rise to considerable variability 



disadvantageous ones, because recombination among the offspring, because most stocks, un- 



and random assortment can occur only when less inbred for many generations, are hetero- 



meiosis is permitted to intervene between zygous for many genes. 



