INSECT ABDOMEN SNODGRASS 



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chamber. Its anterior wall is formed of the venter of the eighth 

 segment, and contains the genital opening (fig. 44 A, c). 



The eighth segment is much reduced and is mostly membranous, 

 but in the queen it forms a distinct oval annulus (fig. 44 A, VII IT, 

 VII IV) at the anterior end of the sting chamber surrounding the 

 basal parts of the sting and the proctiger. The dorsum of the eighth 

 segment is a weakly sclerotized fold across the back (fig. 40, VIIIT), 

 but on each side it contains a large tergal sclerite, the lamina spiracii- 

 laris (figs. 40, 44 A, Lsp), in which is situated the eighth spiracle. 

 From each spiracular plate a membranous fold (fig. 44 A, VIIIV) 



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Fig. 40. — End of abdomen of Apis mellifica, worker, with left side removed, 

 exposing the sting chamber containing the external parts of the stinging appa- 

 ratus and the proctiger, and showing also the poison sac and a part of the rectum. 

 (From Snodgrass, 1910.) 



extends downward on the anterior wall of the sting chamber, and 

 these folds, which are continuous ventrally beneath the genital open- 

 ing, represent all that is left of the eighth venter. 



The genital structures contained in the seventh segment, as well as 

 the eighth segmental annulus itself, are much better developed in 

 the queen than in the worker. By depressing the seventh sternum 

 of the queen there is to be seen on the anterior wall of the sting 

 chamber, immediately before the base of the sting, a triangular de- 

 pression (fig. 44 A, a) between the folds of the eighth venter 

 {VIIIV). Within this depression is a large, transverse median 

 genital aperture {c) and, at the sides of and below the latter, two 

 other openings {d, d). The median orifice leads into a large median 



