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Psyche 
[December 
tures (histories unknown), their nerve cords were severed and their 
oocytes were measured on the day they gave birth or aborted their 
odthecae. Five females gave birth and 3 extruded odthecae containing 
well developed embryos in 19 to 33 days after the operations. In every 
female the oocytes grew, as a result of nerve severance, and measured 
4. 241+10.33 mm. At ovulation the mature oocyte is 5.86±0.O4 mm. 
(N=ii) and the new basal oocyte is o.97±o.oi mm. (N=6). 
Normally at parturition the oocytes are 1.67+10.03 mm. long (N = 
10). Gestation in this species lasts about 95 to 103 days. Nerve cord 
severance at least 33 days before parturition eliminated the inhibition 
of the corpora allata resulting from the presence of the egg case in 
the uterus. 
Leucophaea maderae: The odthecae of 7 females were removed and 
part of the egg cases were implanted into the abdomens of the female 
donors. Five females which had their egg cases removed and im- 
planted 10 to 15 days after oviposition, ovulated 61 to 65 days later. 
This is about the time one would expect ovulation after removal of 
the ootheca (fig. 11). One female had oocytes 2.18 mm. long 65 days 
after an implant (made 10 days after ovulation). One female whose 
ootheca was removed and implanted 22 days after ovulation had 
oocytes 5.14 mm. long 41 days later. Four females whose odthecae 
were removed 14 to 40 days after ovulation and had a wax “ootheca” 
inserted into the uterus showed no yolk deposition in the oocytes 
(1.05+10.05 mm.) 58 to 65 days later. 
The implantation of uterine eggs into the abdomens of females did 
not prevent the oocytes from maturing. The results with wax “odthe- 
cae” insertions indicate that the corpora allata may be inhibited by 
pressure of the ootheca in the uterus. 
To determine whether there was a hormonal influence on oocyte 
development in Leucophaea, Engelmann (1957) removed the eggs 
from the uterus and implanted about one half of the ootheca into the 
abdominal cavity. He found that the eggs (in the ootheca) still 
affected the corpora allata when they were implanted into the abdo- 
men (as they did when in the uterus). To rule out any possible effect 
of a mechanical pressure on the abdomen, or the effect of other sub- 
stances resulting from decay of tissues ( i.e. decaying implanted uterine 
eggs) he implanted paraffin blocks, muscle tissue, or agar blocks of 
about the size of half an ootheca after removal of the egg case. These 
implants did not inhibit the corpora allata and Engelmann concluded 
that the arrest of the corpora allata was not caused by mechanical 
pressure. However, it should be pointed out that pressure exerted by 
an implant in the abdominal cavity may be quite different from pres- 
