480 LÉPIDOPTÉROLOGIE COMPARÉE 



case, in tbe reciprocal crosses between hirtaria and pomonaria 

 within the limits of expérimental error. 



There only remains to be discussed the curious fact that very 

 strong inbreeding of pomonaria, lapponaria, and zonaria before 

 Crossing, produces, on rare occasions, a few females. The only 

 explanation one can offer is that such a procédure tends to 

 restore exceptionally, one or other of the species to its original 

 State, and, as they are ail derived from the same ancestral form, 

 the sex determining characters would be of the same nature as 

 between two members of the same species and thus females would 

 resuit. That inbreeding does disturb in some way the balance 

 of the sexes is a well-known fact, although, personally, I hâve 

 only observed it in the case of closely inbred Zonosoma orbicii- 

 laria, which produced only females. 



It must be noted, however, that no amount of inbreeding with 

 hirtaria has, in the case of the cross with zonaria female, ever 

 produced a female. 



F. The gynandromorphism of the secondary hybrids. 



Anatomical examination of several thousand primary hybrids 

 has revealed the fact that except for one spécimen, which was 

 patently a gynandromorph, ail of the imagines were perfectly 

 maie or perfectly female. In no case was there the slightest trace 

 of a mixture of the sexual organs, such as is displayed in the 

 female of Smerinthus hybrid. hybridus. 



Yet, in the case of 10 secondary hybrids bred, and about 

 50 pupae of a similar nature obtained, ail, without exception, are 

 gynandromorphs. Why hâve we this différence ? The proportion 

 in the primar)^ hybrids is not différent from what is observed in 

 pure species. 



Resulting from their hybrid origin, there is a marked degene- 

 ration observable in the ova produced by hybrid females, and 

 probably this is accompanied by a similar tendency in the sperma- 

 tozoa of the maies. The secondary hybrids, produced themselves 



