in Pedigree Moth-hrecdinq. 



95 



Sleeved Illunaiii.\. 



Sleeved Illustr.\ijia. 



It will be observed in the case of the spring emergence 

 that when the winter was well over and the pupae may 

 have been supposed to be ripe for emergence on suital^le 

 conditions presenting themselves, the illunaria nearly all 

 emerged in from 3 to 5 days after the forcing was 

 applied, more than half of them on the 4th day, and the 

 illustraria nearly all emerged in from 2 to 4 days after 

 the forcing was applied, more than half of them on the 

 3rd day.] It seems as if under the most favourable 

 conditions it took several days to go through the changes 

 that intervene between the comparatively torpid central 

 period of pupal existence and the winged stage, and that, 

 as the icing experiments appear to indicate, a "cold 

 snap " occurring during any part of this active later 

 period may suspend these changes for a time, but 

 produce no great eifect besides. I suppose there is a 



