218 Psyche [December 
DAYS AFTER REMOVING OOTHECA FROM UTERUS 
Fig. 12. Relationship between age of ootheca when removed from the 
uterus, and recovery of receptivity in N. cinerea. Numbers in circles — 
number of insects used. Numbers in parentheses = number of days females 
were pregnant when their oothecae were removed. Numbers under the 
parentheses — mean length (mm.) ± standard error of the oocytes meas- 
ured <24 hr. after mating. Numbers in brackets — mean days ± standard 
error for return of receptivity. Solid triangles = virgin females; all other 
groups had mated prior to ovipositing. All females with males continuously 
until they mated ; females examined daily for spermatophores. The per 
cent mating is expressed as accumulative data. 
that fewer sperm are present in the smaller consecutively formed 
spermatophores. One experiment was performed to determine the 
oviposition behavior and subsequent receptivity of females that were 
mated to males that had mated consecutively; in all cases a sper- 
matophore was transferred. Of 150 females mated to virgin males, 
only 2 (1%) aborted their oothecae prematurely and the eggs were 
