On the. Seasonal Dimorphism of Butterflies. 79 



cold on the pupae of this brood to produce the 

 winter variety Belemia, whilst, on the other hand, 

 the pupse of the winter generation by the influence 

 of warmth would be made to revert more or less 

 completely to the form Glance. It is by no means 

 to be understood that the species would actually 

 comport itself in this manner. On the contrary, I 

 am of opinion that in this case also, the winter 

 form is primary. The northward migration (from 

 Africa to south Spain) would be quite insufficient, 

 and the winter form is now found in Africa as well 

 as in Spain. 



