188 



MULTIPLE FACTORS 



times, etc. It would require a large number of off- 

 spring to prove the multiple factor hypothesis if the 

 reappearance of the grandparental types be de- 

 manded for such a proof. 



p 

 1 



F 



1 



F 



z 



Fig. 58.— Short-eared by lop-eared rabbit. Fi, son of last ; Fo, daughter 



of Fi by his sister. (After Castle.) 



Several excellent cases of multiple factors have been 

 worked out with Indian corn. Height of plant 

 (as a concomitant of its vigor), length of ear, and 



