92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



the cavity of the bulb. The plates are not separable from a large 

 spongy body beneath them that forms the dorsal wall of the bulb 

 cavity and thins out on the sides, where it is continued into a chitinous 

 intima covering the rest of the lumen. From the inner wall of the 

 spongy body two small, posterior triangular plates (E, h) project 

 laterad of the dorsal plates as free flaps into the cavity of the bulb. 



In most drones taken in late summer the endophalHc bulb is found 

 to be filled with a dense mass of spermatozoa and fine granular 

 matter, which, in specimens preserved in alcohol, forms a compact 

 body molded into the shape of the interior of the bulb (fig. 30 H). 

 This body is termed by Zander (1911) a Sam-enpatrone ("seminal 

 cartridge," cartouche of Leuenberger, 1929). It is not, however, a 

 true spermatophore, or sperm-containing capsule, since it has no 

 retaining wall ; its outer surface in preserved specimens is dense and 

 regular, but is minutely pilose because of the great number of sperm 

 tails projecting from it. 



The discharge of the spermatozoa is accomplished by eversion of 

 the endophallus. The endophalHc walls being entirely nonmuscular, 

 eversion of the organ is brought about naturally by a strong muscular 

 compression of the abdomen, and this function of the abdomen in 

 the male probably accounts for the great size of the abdominal muscles 

 of the drone (fig. 29 B) as compared with those of the queen or 

 worker (fig. 28 A). Artificially a partial evagination of the endo- 

 phallus is easily produced in a fresh specimen by pressure on the 

 abdomen, and is often seen in killed specimens (fig. 30 G). Bishop 

 (1920), however, describes methods by which a complete eversion 

 can be induced, and Leuenberger (1929, fig. 17) gives a photograph 

 of the fully everted organ. 



In the first stage of the endophalHc eversion, or the condition 

 usually produced by artificial compression of the abdomen, the bursa 

 is turned entirely inside out (fig. 30 G, Brs) with the everted cornua 

 {be) projecting upward and outward from its sides. The stretched 

 cervix of the organ now traverses the lumen of the bursa and opens 

 between the bases of the cornua. It is generally supposed (though 

 apparently never observed) that in the copulatory act the cornua, or 

 pneumapophyses, enter the lateral pouches of the female genital cham- 

 ber (fig. 28 D, ;') ; probably the cervical aperture on the distended bursa 

 is held close to the opening of the median vaginal pouch {g), and 

 the endophalHc bulb then everted through the cervix into the vagina. 

 Zander (1911) contended that the bulb is not everted, since in newly 

 mated queens he found it in the uneverted condition grasped between 

 the base of the ovipositor and the seventh abdominal sternum. On 



