ALIMENTARY CANAL IN THE BEE 555 



bee. Between them are disjiosed the granular contents (g) and two 

 blood (?) corpuscles. Duboscq's fluid ; Mann-Holland's stain. Zeiss ; 

 ob. j^2 horn, imm., oc. 4. 



Fig. 11. — Part of the epithelial wall of the stomach in the bee dissected 

 in May, Between the glandular cells is arranged the cry]>t, the cells of 

 which also discharge a secretion accumulating in the globular vacuole 

 {vc). The epithelial cells bear on their surface the ' hairy ' layer of proto- 

 plasm (tvp). Duboscq's fluid ; Giemsa staui. Zeiss ; ob. J^ hom. imm., 

 oc. 4. 



Fig. 12. — Part of the wall of the stomach of the same bee. In the 

 ' hairy ' layer of the epithelial cells are visible swellings of the superficial 

 layer of protoplasm corresponding to the vesicular evaginations of the cells 

 observed in the mid-gut of the larvae of Ptychoptera by Van Gehuchten. 

 Mann- Holland stain. Zeiss ; ob. Jg hom. imm., oc. 2. 



Fig. 13. — Tangential section of the wall of the stomach in the bee. 

 The rounded evaginations of the epithelium with cryptae at their bottom 

 are visible in section. Duboscq's fluid ; Giemsa's stain. Zeiss ; ob. DD, 

 oc. 4. 



Fig. 14. — Longitudinal section of circular fibres of the muscular mem- 

 brane of the stomach, sp, sarcoplasm. Giemsa's stain. Zeiss ; ^^, oc. 4. 



Plate 17. 



Fig. 15. — Longitudinal section of a fibre from the muscular membrane 

 of the stomach of the bee ; the abundance of sarcoplasm (sp) with nuclei 

 in it {n) is visible (see fig. 16, PI. 17). Haematoxylin, eosin. Zeiss ; ob, JL 

 hom, imm., oc, 4, 



Fig. 16. — Transverse section of muscle-fibres from the circular mem- 

 brane of the stomach in the bee. The fibres are rich in sarcojilasm. The 

 nucleus is disposed beyond the area occupied by the myofibrils. Haema- 

 toxylin ; eosin. Zeiss ; ob. ^^ hom. imm., oc. 4. 



Fig. 17. — Pare of transverse section of epithelium of the small intestine 

 of the bee. In the cells are visible vacuoles with secretion and the striated 

 superficial layer of plasm {ds) covered with a chitinous cuticle (c). Zenker 

 formol ; Mann-Holland's stain. Zeiss ; ob. ^, oc. 4, 



Fig. 18. — Transverse section of the fibre of the muscular membrane of 

 the small intestine in the bee. The fibre is thick ; nuclei are disposed 

 along the axis of the fibre surrounded exteriorly by tufts of myofibrils. 

 The fibre is enveloped in the perimysium. Duboscq's fluid ; Heidenhain's 

 iron haematoxylin. Zeiss ; ob. j\ hom. imm., oc. 4. 



Fig. 19. — Rectal glands in the wall of rectum. Total surface preparation. 

 Alcohol ; borax carmine. Ob. Winkler 1, oc. 0. 



Fig, 20, — Schematic structure of rectal gland. The drawing represents 

 the wall of the rectum with half of the gland inserted in its wall. Rectum 

 represented exteriorly. 



