139 



Tlie egg cases were at first kept in open vials, after removing 

 them from the jar, bnt the eggs dried out too much, so that 

 many of them did not emerge at alL Later, in order to deter- 

 mine how long she conld produce fertile eggs, after the death of 

 the male, I placed each ootheca in a corked vial on the day tliat 

 it was laid, and left these in the table drawer. Those that I 

 treated in this wav — the 27th, 28th, 33rd, and 34th cases — 



