152 
Crews 
done with Paul Licht on the factors control- 
ling the sexual refractory period following 
the breeding season. 
CONTROL OF SEASONAL OVARIAN 
RECRUDESCENCE IN THE LIZARD, 
Anolis carolinensis 
All of the experiments on the role of the 
male in seasonal ovarian recrudescence (OR) 
were conducted during the period of winter 
dormancy, thereby insuring an unchanging 
baseline measure of ovarian activity against 
which the effects of the various experimental 
manipulations could be assessed. 
The same procedure applied to all of the 
experiments. Animals were shipped to the 
laboratory within a day of capture. Four 
days after their arrival, they were divided 
into groups and placed in environmental 
chambers. The chambers simulated the natu- 
ral habitat as closely as possible and were 
programed to provide an environmental 
regime consisting of a 14 :10 LD photic cycle, 
a daily thermal cycle of 32 C during the 
photoperiod and 23 C during the dark phase 
of the cycle, and a constant relative humidity 
of 70-80 percent. During each experiment, 
weekly samples of representative females 
were taken from the various groups and 
their reproductive condition determined. 
Environmental factors regulating ovarian 
recrudescence 
The purpose of the initial experiment was 
to determine first whether the environmental 
regime would stimulate out-of -season ovarian 
recrudescence in reproductively inactive 
winter-dormant females (Crews, et ah, 1974). 
If ovarian activity could be stimulated in 
this manner, would the presence of other 
females or males alter the pattern of ovarian 
response? Finally, if the presence of con- 
specifics was important, was the physiologi- 
cal state of the conspecific critical? 
In answer to the first question of whether 
vitellogenesis (yolk deposition) could be 
environmentally stimulated in winter-dor- 
mant females, I found that an increasing 
percentage of isolated females (as well as 
females in other experimental groups) had 
yolking follicles, whereas females in the field 
(Field Control) failed to show any signs of 
reproductive activity (Fig. 3). The presence 
of other females (Female Group) did not 
appear to be any more stimulatory than the 
environmental regime alone. However, the 
presence of intact males, whether in the 
Female-Male group, or in the Isolated Pairs 
group, significantly facilitated environment- 
ally induced OR. Finally, the physiological 
state of the males was an important factor 
since females housed with castrated males 
exhibited a rate of environmentally induced 
ovarian activity that was not significantly 
different from that shown by isolated females 
and females in the all-female group. 
In addition to a less rapid rate of OR, 
isolated females and females housed together 
or with castrated males laid only unshelled 
eggs. This was an important observation 
since Licht (1973) had demonstrated pre- 
viously that the laying of shell-less eggs in 
A. carolinensis is due to subnormal pituitary 
gonadotropin secretion. 
This experiment demonstrated therefore 
that, while an unseasonal environmental re- 
gime will stimulate out-of-season OR in 
winter-dormant females, the presence of in- 
tact males strongly facilitates OR, most 
likely through an effect upon gonadotropin 
secretion in the female. 
Can this male-facilitated rate of OR be 
increased further? To test the hypothesis 
that OR would be maximally stimulated if 
winter-dormant females were exposed to 
males exhibiting environmentally induced 
sexual activity, freshly captured winter- 
dormant females were housed in cages each 
containing five sexually active males (Crews, 
1974a). Results from this experiment, how- 
ever, were totally unexpected. 
In contrast to the gradual increase in 
ovarian activity by females housed with cas- 
trated males and the rapid rate of recrudes- 
