278 G. H. BISHOP 
again normally as the bulb everts, since the bulb itself would 
not enter the orifice. The presence of this bulb in the bursa 
would operate, by depressing the ventral floor, in the same 
manner as the pneumophyses do; that is, the vaginal orifice 
would be widely opened, and the dorsally recurving end of the 
ejaculatory duct could enter it. More evidence is needed on this 
phase of the matter. 
The distance to which the drone organ enters the vagina may 
be judged from a consideration of the relative sizes of the respec- 
tive parts. In figure 1, A and B, are drawn in outline the dorsal 
view and the profile of the female genital tract, and in figure 1, 
C, the lateral view of the end of the everted drone organ. The 
vagina can undoubtedly be expanded to a larger dimension than 
its relaxed state would show, but it is hardly possible that the 
large bulb with its heavy chitinized plates could be made to 
enter the vaginal orifice, to say nothing of turning inside out as 
it entered. It seems certain, therefore, that the eversion of this 
part takes place in the outer space comprising the bursa copu- 
latrix and the region posterior to it (the genito-anal vestibule). 
The curved end of the ejaculatory duct is probably normally 
the only part of the drone organ to remain in the vagina proper, 
though, as stated, the section of the penis preceding the bulb 
in eversion probably lodges there momentarily. The bulb would 
then lie between the dorsal and ventral genito-anal plates, and 
its size is such as would cause the pronounced gaping of the 
queen’s last segment, and which would leave the tips of the 
brown chitinized plates on the dorsal side of the bulb to protrude 
visibly from the genital aperture, as may usually be observed in 
newly mated queens. 
DESCRIPTION OF FERTILIZED QUEENS 
Of the eight queens the fertilization of which was successful 
and the time of mating recorded, four were fixed and sectioned 
for histological study and four were dissected in the fresh con- 
dition. The following data describe the gross appearance of the 
oviducts, vagina, spermatheca, and, when present, the penis of 
the drone, with which the queen habitually returns to the hive, 
