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. 



F 

 t 



F 



z 



FIG. 58. Short-eared by lop-eared rabbit. FI, son of last; F 2 . 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 



