NO. 2 HONEY BEE — SNODGRASS 9I 



The endophallus is the intromittent organ of the bee ; during mating 

 it is everted, in part or entirely, and inserted into the genital tract 

 of the queen. Structurally the endophallus is differentiated into three 

 major sections : first, opening directly from the phallotreme, is a 

 large sack, or bursa (fig. 30, F, Brs) ; the second, middle part is a 

 narrowed neck, or cervix (Cer), connecting the bursa with the third, 

 innermost part, which is a large, thick-walled bulb (Bib). The 

 ejaculatory duct (Dej) opens into the anterior end of the bulb. 



The endophallic bursa (fig. 30 F, Brs) has tough membranous 

 walls, which are more or less collapsed and folded in the retracted 

 condition. From the sides of the bursa project a pair of large, taper- 

 ing, thin-walled, crumpled cornua, or pneumapophyses (be). In the 

 ventral wall are two somewhat elevated dark areas, the first (c) 

 quadrate in form, the second (d) shield-shaped. Internally these 

 areas are seen to be flat pockets of the bursal wall covered with a 

 dense growth of small, dark spines or thick curved hairs. Elsewhere 

 the inner walls of the bursa are closely dotted with minute spicules, 

 but the linings of the cornua are bare, though wrinkled and finely 

 alveolate in appearance. 



The cervix of the endophallus is ordinarily compressed into an 

 irregular shape (fig. 30 F, Cer), but when stretched out straight it is 

 seen to be a wide tube with tough membranous walls. Along the length 

 of its lower wall runs a rounded fold (e) that forms internally a 

 ventral gutterlike channel. Externally the fold is crossed by a series of 

 V-shaped elevations conspicuous by their dark color, which is due to 

 an internal covering of small spines. Similarly, an internal spine- 

 covered patch at the posterior end of the dorsal wall appears externally 

 as a triangular or cordate dark area (/). Near its anterior end the 

 cervix bears dorsally a large diverticulum (fib), known as the pinnate, 

 or fimbriate, lobe because its margins are deeply cut into flat, over- 

 lapping lobules. 



The large endophallic bulb (fig. 30 F, Bib) has a complex structure, 

 which is not fully understood since it has never been thoroughly 

 studied by histological methods. In the distal half of its dorsal wall 

 are two parallel, elongate, strongly sclerotic plates (E, F, g), which 

 are usually shown in illustrations as external structures, but they are 

 covered by a thin outer tunic that forms a fold in the groove between 

 them and is continued over the rest of the bulb. The plates, therefore, 

 would appear to be sclerotizations of the inner wall of a flat dorsal 

 pouch of the bulb lumen ; when the covering tunic is removed the 

 smooth outer surfaces of the plates are exposed (E) and the tapering 

 posterior ends are seen to project freely into the posterior part of 



