June, 1907.] JOUTEL : PhILOSAMIA AND CaLLOSAMIA CROSSES. 103 



species to a greater degree, and there was not that desire to mate in 

 the male as there was in the opposite cross, while the female had the 

 same repugnance to the cynthia cj* as there was in the reverse case, so 

 that these matings were few. 



The eggs resulting from these crosses were not to be distinguished 

 from normal proinet/na eggs. The eggs of the single matings gave 

 larvae, a few of which were not to be distinguished from normal 

 proinethia, but most of them had heavy black bands on the segments, 

 a few being nearly all black. At the first moult we were agreeably 

 surprised to see the fine cream-colored cynthia-WV^ larvge that crawled 

 out of the first s\.a.gQ protnethia skins. So astonished were we that had 

 we not seen them we would have supposed that cyjithia larvse had got 

 in the jar by accident. In the next stages the dual parentage of the 

 larvae was very evident. Colored figures of these stages I hope to pub- 

 lish later with the figures of the resulting moths. 



The cocoons of these were very small and were either spun between 

 two leaves or in the folded corner of one; the tendency to stem- 

 making was partly lost, some few not making any at all, others spin- 

 ning a layer of silk to the leaf stem. In this lot several crawled out 

 of the cocoons when nearly completed, but we did not have this hap- 

 pen in the crosses that had cynthia females. 



The sum of the results of crossing these species both ways shows 

 that it is the cynthia which has the greater effect on the resulting 

 hybrid larvae and it remains to be seen what the results will be in the 

 imago. 



The cocoons show less specialization than any of the parents, but 

 have the cynthia characters predominating. 



Miss Soule gives a wrong interpretation of the pulling in of the 

 loose threads at the opening of the cocoon. What I have observed is 

 that the larva takes a bunch of threads in its mandibles and pulls these 

 threads in by suddenly retracting the head and front segments, mean- 

 while liolding on by its '■'■props " to the bottom or side of the cocoon. 



Since writing the above Miss Soule has informed me that she had 

 also given some notes on these hybrids in Psyche for November, 1902. 

 My results, however, were different from hers in that all my larvje of 

 cynthia d^ and proinethia ? were of the same type, and only differed 

 slightly in color, though a larger amount of material might have 

 shown different results. The bifid horn on the eleventh segment she 

 mentions is also occasionally bifid in pure proviethia. 



