J. W. H. Harrison and L. Doncaster -231 



(3) Dominance of characters derived from the undoubtedly weaker 

 Ithi/siae. 



This was treated at length and shown to depend on the fact that, 

 highly specialised as the Ithysiae are, they are yet, in many points, the 

 most primitive genus of the group in spite of the fact that, for the most 

 part, the genus Lycia is nearer the common phylogenetic ancestor of 

 both genera. In other words, we have a recurrence of common ancestral 

 features. 



(4) The superior influence of the mule. 



This is an experimental result that. I have noted in practically all of 

 the hybrids I have reared, not only in this family, but amongst the 

 Ennomids and Larentiads likewise. No reasonable explanation of this 

 fact has ever been suggested. 



(5) The refusal of the food plants of the Ithysiae. 



I have pointed out that this probably depends on the fact that, in 

 general, the Boarmiads are an arboreal group and that the Ithysiae 

 have almost certainly abandoned the family habit ; there is thus latent 

 in them a tendency to eat the same food jjlants as the Poecilopsis-Lycia 

 fraternity. 



(6) The abnormal sex proportioJis yielded. 



Four of the hybrids, 



Lycia hybr. denhami, 

 L. hybr. bidoveci, 

 P. hybr. smallviani, 

 P. hybr. helenae, 



exist only in the male sex under normal conditions. 



It must not be supposed that this failure to give females is restricted 

 to this compact group of genera, for I have observed it in the case of 

 two other crossings I have made amongst the Boarminae, viz. : 



(1) Epione paraUelaria ^ x E. apiciaria ? = hybr. isabellae 



and (2) Tejjhrosia, crepuscularia c^ x T. bistortata % = hybr. bacoti. 



Strong inbreeding of the parents producing two of the above hybrids, 

 on one occasion, resulted in the production of odd females, but the same 

 procedure was without effect whenever Lycia hirtaria took part in the 



cross. 



16—2 



