474 LÉPIDOPTÉROLOGIE COMPARÉE 



C. The superlor influence of the maie. 



In this group this is not rea.dily explained. It is easy to say 

 with other observers, that the maie is the more conservative form, 

 and therefore bears a greater number of ancestral déterminants; 

 this would mean that we ought to hâve a product nearer to the 

 original type but such is not the case. In many cases it is the 

 female which is nearer the ancestral stock and an approach to 

 the maie necessarily means a step from the common ancestor. One 

 can only say that this is an expérimental ly developed law con- 

 firmed by the results of ail similar experiments. 



D. Distaste for the food plants of Ithysia. 



As was demonstrated above, the Ithysia group hâve been sup- 

 planted and dîsplaced from. their old habitats in the long distant 

 past by the more vigorous Lycia group. Driven from the wood- 

 lands to open ground, in the first place they would be forced to 

 a diet of some low shrubs, not very distinct in character from 

 what they were formerly accustomed to. Such plants they would 

 find in the lower growing species of Ko sa and Salix, e. g. Rosa 

 spinosissima, Salix repens. Thenoe, a graduai, but not perfect 

 transition, to AchilLea Lotus, Artemisia and similar plants has 

 been made. The tendency is therefore présent, from both sides, 

 to feed on hawthorn, etc., and thèse foods are adopted. 



E. The sex détermination in the hybrids. 



When we come to examine the proportion of the sexes produoed 

 in thèse hybrids, a remarkable séries of phenomena is observed. 



Four of the crossings : 



Lycia hirtaria çS x Ithysia zonaria Q = hybr. denhami; 

 Pœcilopsis lapponaria cf x /. zonaria Q = hybr. smallmani ; 

 Pœcilopsis pomonaria cf x /. zonaria Q ^^ hybr. helenœ ; 

 Lycia hirtaria cT x /. grœcaria Q = hybr. buloveci; 



