FERTILIZATION IN THE HONEY-BEE 231 
each of these, leads a vas deferens, proximal to the testis sharply 
coiled (f), and distally expanded into a seminal vesicle (e). 3) 
Distal (posterior) to the vesicle again, the vas deferens curves 
sharply (h) to enter the third element, the accessory gland (d). 
This organ extends anteriorly to a region slightly beyond the 
testis, the rudiment of which in the mature drone is usually 
applied dorsally to the tip of the gland (text fig. 1, g). 
Text fig. 2 Diagrams of drone’s organs, showing uneverted, partially everted, 
and completely everted relationships of the various portions, in A, B, and C, 
respectively. a, posterior or proximal tubular portion of the penis with modi- 
fications for facilitating copulation, e, f, g; b, bulb portion of penis, with lateral 
chitinous plates shown in black; c’, proximal end of ejaculatory duct c, expanded 
where it joins the bulb of the penis; d, the mucous glands. For further explana- 
tions see text. 
In development, each vas deferens grows back from the testis 
sheath until it meets, ventrally, a cup-like invagination of the 
ninth segment of the abdomen which is to form the penis and the 
ejaculatory duct. The vas deferens fundament then curves back 
on itself to form a hook like the letter J, later, becoming a U. 
The recurved tip of the J forms the mucous gland; the stem the 
seminal vesicle. A branch of the ejaculatory duct penetrates 
