1910] Girault and Sanders — Chalcidoid Parasites 19 
the light were removed and released to be used in an experiment to 
test artificial propagation. Unfortunately, these were not counted in 
regard to sex, so that it is unknown whether the females greatly 
predominated, a result which we were led to suspect from the fact 
that this sex appeared to be more attracted to light; for the first 932 
individuals taken from the experiment, after all emergences, were 
females, dead in the exit-tube, which alone was light. Lot No. 3 is 
the most complete record made, none of the emerging parasites having 
escaped, and we are inclined to think that it represents the actual 
ratio of the sexes, the females slightly predominating. 
The proportion of the sexes in a small number of the parasites which 
hibernated as larvae, hence the parents of the first spring generation, 
was as 37 males are to 61 females; these emerged during the last day 
of April, 1909. ‘Their descendents or parents of the 2d generation 
were also of mixed sexes, being the progeny of fertilized females, there 
being 24 males to 45 females, which emerged on May 25, 1909. 
I. Emergence of the Adult. In general, it may be stated that the 
adult parasites emerge from the host puparium through from 1 to 3 
circular holes, situated variously, usually in the dorsal or dorso-lateral 
aspect; and when more than one exit-hole, the two or three are usually 
scattered or widely separated. The manner of emergence does not 
differ for sex. The exit-hole varies in diameter from about 0.75 to 
1.50 mm.; it is usually larger and single when the host is Musca or 
Chrysomya and smaller when Phormia, though this difference may 
be more apparent than real. Individual exit-holes may of course 
vary considerably in shape; for rarely it may involve the whole of one 
end of the host puparium and is then relatively very large and irregular. 
The margins of the exit-holes are always jagged or serrate, showing 
that the adults gnaw their way out. Specific instances may better 
illustrate. 
From a single puparium of Musca domestica, 1 male and 6 females 
issued from a single dorsal exit-hole just behind the head end; several 
parasites of both sexes issued from another puparium from a hole in 
the dorsal aspect of the 7th segment; several adults of both sexes 
issued from a third puparium through two exit-holes in the cephalic 
and caudal segments respectively. Again, 1 male and 2 females 
emerged from a more irregular exit-hole in the dorso-lateral aspect of 
the caudal or anal segment of the host. Ina last case recorded, 2 jo 
and 4 2 @ issued from a single hole near the cephalic end of the host. 
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