64 THEORY OF EVOLUTION 



(fig. 28 to right) only one of which is like the 

 male. Here the analysis of the breeding data 

 shows the possibility of explaining this case 



FIG. 28. Papilio polytes, with three types of female to right 

 and one type of male above to left. 



as due to two pairs Mendelian factors which 

 give in combination the three types of female. 

 Taking these cases together, they furnish 

 a much simpler explanation than the one pro- 

 posed by Darwin. They show also that char- 

 acters like these shown by wild species may 

 follow Mendel's law. 



