554 E. N. PAVLOVSKY AND E. J. ZARIN 



EXPLANATION OF PLATES 15, IG, AND 17. 



Plate 15. 



Fig. ]. — Vontriculo-intestinal canal of the worker-bee in summer. 

 Large intestine of small size. 



Fig. 2. — Same in clrone. Stomach much longer than in the worker-bee. 



Pig^ 3 — Intestine of hibernating bee. Large intestine filled with faeces 

 and therefore presenting the largest portion of the intestine in dimensions. 

 The arrows denote the points at which the intestine was cut for the pre])ara- 

 tion of extracts from it. All the three figures were made with Zeiss' 

 l)inocular microscope, ob. I 55, oc. 1, 



Plate 16. 



Fig. 4. — Schematic longitudinal section of the bod.v of the worker-bee with 

 its organs of digestion. Combined, from two figures of Zander's monogra])h. 

 The arrows on the left show the subdivision of the body into head, thorax, 

 and abdomen, whereas the ones on the right denote the subdivision of the 

 intestine into the fore-, mid-, and hind-guts. The subdivisions mentioned 

 do not correspond one with another, as the fore-gut (o, i) passes through 

 the head, thorax, and part of the abdomen. 



Pig 5 — Transverse section of the crop on the level of the stomach 

 valve, cd, cuticle of the surface of the valvular capitulum ; ic, cavity 

 of the croj). Haematoxylin ; eosin. Zeiss ; ob. AA, oc. 4. 



Fi(T. 6. — Slightly oblique section of the stomach of the bee. Its cavitj'^ 

 is filled with a very great number of ])eritrophic membranes (p) dis^josed 

 in concentric layers one on another. Zenker formol. Heidenhain's iron 

 haematoxylin. Zeiss ; ob. AA, oc. 1. 



Fig. 7. — Part of transverse section of the stomach of the bee. A cr^'pt 

 in the depth of the c])ithelial fold is visible. Above the crypt is a vacuole 

 with secretion. The hibernating bee was fixed in .4pril. Dulioscqs fluid. 

 Mann-Holland stain. Zeiss ; J^ ^^^^- "nm-» oC" 0. 



Fig. 8. — Part of the wall of the stomach in the bee, dissected in May. 

 The section has passed obliquely, on account of which the cells of the folds 

 appear to be set on slender peduncles and interrupted. Zeiss : ob. ^.. 

 horn, imm., oc. 1. Duboscq's fluid ; Giemsa stain. 



Fig. 9. — Transverse section of the wall of the stomach to shoAv the 

 formation and the rubbing oft' of the peritrophic membranes (p) developing 

 at the expense of the ' hairy " layer of the epithelial plasm (icp). Above 

 the crypt (k) the vacuole displacing the ' hairy ' layer of the plasm is 

 situated. Zenker formol : Heidenham's iron haematoxylin. Zeiss ; ob. j\ 

 horn, imm., oc. 1. 



Fig. 10. — Peritro])l\ic membranes in the cavity of the stomach of the 



