190 
Psyche 
[December 
oothecae were removed 23 to 76 days after oviposition had oocytes 
1. 1 9 ±0.04 mm., 34 to 63 days later. Fourteen females that had their 
oothecae removed O to 77 days after ovulation had developed oocytes 
3.72dbo.30 mm. long, 34 to 71 days later. It is unknown why about 
45% of the females failed to show oocyte development after removal 
of the odtheca ; the presence of degenerating oocytes that were not laid 
in the first ovulation may account for some of these cases. 
Byrsotria fumigata: In Byrsotria gestation lasts from 71 to 82 days 
(x— 76.2+11.4; N = 6). The basal oocytes at parturition vary in 
length from 1.43 mm. to 1.71 mm. (x= 1. 53+0.04 mm.; N=io). 
The second ovulation occurs 21 to 30 days (x— 24.8 ±1.6; N = 5) 
after parturition. Oocyte development during pregnancy in mated 
females is inhibited and no yolk is deposited until after the young are 
born. 
Five mated females had their oothecae removed at various periods 
during pregnancy. One whose ootheca was removed 27 days after 
ovulation oviposited 45 days later. Two females whose oothecae were 
removed 28 and 40 days after oviposition had practically mature 
oocytes, 5.98 mm. and 6.22 mm. (fig. 14B) respectively, 32 days later. 
The oocytes ( 1.23 and 1.29 mm. long) of two females whose oothecae 
were removed on the first and thirty-first day of pregnancy failed to 
develop when examined after 75 and 32 days. The oothecae of 10 
virgin females were also removed with the following results. Three 
females whose oothecae were removed 29 to 34 days after ovulation 
had mature oocytes that were being resorbed 53 days later. One 
female whose ootheca was removed 38 days after oviposition ovulated 
again 39 days later. Six females whose oothecae were removed from 
1 to 24 days after oviposition failed to develop their oocytes (x=i.53 
±0.05 mm.) when examined 35 to 59 days after the operations. In 
the mated and virgin females that failed to develop oocytes after 
removal of the oothecae, several unlaid degenerating oocytes were 
present from the previous ovulation which may account for the results. 
Virgin females of Byrsotria that deposit their unfertilized eggs 
normally in the brood sac frequently carry these oothecae for a longer 
period of time than mated females. When the undeveloped eggs are 
finally extruded the ovarian oocytes may be large and contain consid- 
erable yolk in spite of the fact that an ootheca was present in the 
uterus during the entire “pregnancy” period. Thirteen females that 
carried their unfertilized eggs for 71 to 90 days had oocytes 1.5 1± 
0.04 mm. which is normal for the size of the oocytes at parturition of 
mated females. However, the oocytes of 14 virgins that had carried 
their oothecae for 87 to 97 days had oocytes that varied in length from 
