138 



THE SCIENCE OF BIOLOGY 



White 

 (WW) 



Gray (White) 

 (GW) 

 50 



as above 



FIG. 18. Dominance of Gray over White in Inheritance of Coat Color in 

 Mice. The squares represent adult individuals; the letters in parentheses 

 the hereditary constitution. Pi, P2, Fi, etc., as in Fig. 17. 



