vn] THE CASE OF PAPILIO POLYTES 85 



The different kinds of families which each of the three 

 females can produce may be tabulated as follows:— 

 (a) The M form may give either: — 



(1) M only. 



(2) M and mimetics in about equal numbers. 



(3) Mimetics only. 



(£) The A form may give either: — 



(1) M and mimetics in about equal numbers. 



(2) M and mimetics in the ratio of about 1 : 3. 



(3) Mimetics only. 



(y) The H form may give either: — 



(1) M and mimetics in about equal numbers. 



(2) M and mimetics in the ratio of about 1 : 3. 



(3) Mimetics only. 



The males are in all cases alike to look at but it must 

 nevertheless be supposed that they differ in their 

 transmitting powers. In fact the evidence all points 

 to there being three different kinds of male correspond- 

 ing to the three different kinds of female. But they 

 cannot shew any difference outwardly because there 

 is always present in the male a factor which inhibits 

 the production of the mimetic pattern even though the 

 factor for that pattern be present. 



Returning now to the records of the females it 

 will be noticed that although the M form may breed 

 true the mimetics never give the M form alone. Where 

 they give the M form among their progeny they produce 

 mimetics and non-mimetics either in the ratio 1 : 1 

 or of 3 : 1. This at once suggests that the non- 



