284 G. H. BISHOP 
The results of these observations, furthermore, bear out in 
certain details the conclusions of a former paper on the function- 
ing of the sexual apparatus of the drone. They corroborate the 
thesis that the two secretions of the drone which make up the 
sexual fluid—the spermatic fluid of the vesicles and the mucus 
of the glands—have a separate function and are not mixed prior 
to copulation, and that the mucus acts as a plug to prevent 
backflow of fluids, by coagulating in the torn end of the penis. 
The mucus does not form an essential part of the spermatic 
fluid in the sense in which the mucous secretions of some other 
animals do. It forms neither a vehicle for their transfer from 
male to female, nor a nutrient fluid, nor, probably, does it provide 
an important stimulus to their activation (since they separate 
from it, and pass toward the sperm duct evidently under some 
other stimulus). 
Finally, from the two series of observations (that of the former 
paper and this) may be derived a more complete account of the 
mechanics of fertilization in the bee than has been proposed 
heretofore. The stages of this process may be summarized as 
follows: 
1. Coition. The insects meet and clasp face to face; the 
female on being grasped allows the tip of the male’s abdomen 
to enter the genito-anal vestibule; the drone, by explosive con- 
traction of the abdominal walls everts the organ into the female 
genital tract. The pneumophyses first dart into the bursa 
pouches, and by their expansion depress the ventral floor of the 
bursa, and thus pull open the vaginal orifice. As the next region 
of the penis, the median tubular portion with its modifications, 
proceeds to unfold, the pneumophyses are forced back and with- 
drawn, opening the vagina as they retract to the widest possible 
extent, and probably allowing this tubular section to enter the 
pure spermatic fluid, however, or to the injection of both sperms and mucus, 
and how long after copulation egg-laying commenced, their preliminary note did 
not state. Virgin queens will often lay drone eggs if for some reason (defective 
wings; etc.) they are unable to mate, but only after a prolonged period. Queens 
usually lay within two or three days after fertilization, conditions being favorable, 
and sometimes after as short a period as thirty-six hours. 
