FERTILIZATION IN THE HONEY-BEE 273 
superfluous. In the second place, their size is so great that their 
complete expansion into the pockets designed to receive them 
would force the insects apart rather than hold them together. 
Thirdly, the next section of the penis which shows definite adapta- 
tion for resisting withdrawal (fig. 2, C, a, f, g) is so far from the 
pneumophyses that these will be forced back from the bursal 
pouches before the other section everts. Upon careful inspection 
of the queen’s anatomy, especially of the profile of the genital 
tract, another function for these pneumophyses becomes appar- 
ent, namely, to open the orifice of the vagina at copulation, as 
described hereafter. 
The female genital tract has not been adequately described. 
Regions in the genital tract may be distinguished as follows 
(fig. 1, Aand B): 1) a genito-anal vestibule (a), the space between 
dorsal and ventral genito-anal plates, enclosing the shaft of the 
sting and receiving the outlet of the rectum, or anus; 2) the copu- 
latory bursa (b), lying ventral and anterior to the base of the 
sting and extending forward on either side into the bursal pouches 
(c), and which is divided from the vestibule by a slight ridge 
in the floor of the tract (f), and 3) the vagina proper, or unpaired 
oviduct, of which three regions may be distinguished, the poste- 
rior (g), flattened dorsoventrally and lying just anterior to the . 
base of the sting, divided off from the bursa by a very definite 
- constriction (e); medially, a slight enlargement of the lumen 
enclosing a tongue-like organ (h), and opening dorsally into the 
duct to the spermatheca (7), and anteriorly, a region with a T- 
shaped cross-section (n, m), into which open on either side the 
oviducts (0). 
The configuration of this tract will be described in more detail. 
Reference to the figure (fig. 1, A and B) will demonstrate the 
relation of the copulatory bursa to the base of the sting. The 
floor of the genito-anal space (a) is formed by a heavily chitinized 
membrane attached at the lateral margins to the ventral terminal 
sclerite, the anterior margin being free from this sclerite and 
separated from it by aspace. From this margin, which is curved 
convexly to the anterior, extends a thinner and less heavily 
chitinized membrane, to form the ventral wall of the bursa. 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 31, NO. 2 
