1909 



GLEANINGS IN BEE CULTURE 



537 



latter fibrils, together 

 with the longitudinal 

 ones, serves to squeeze 

 out the last drop of 

 honey either into the 

 gullet or chyle-stomach. 



At the base of the 

 honey-sac is a beautiful 

 organ, the stomach- 

 mouth, which is not 

 easy to describe, but 

 which I hope can be 

 understood with the 

 help of Figs. 1 — 5. The 

 organ consists of four 

 lips I Fig. 5 1 , which form 

 tlirough the whole 

 length a chasm in the 

 shape of a cross (Fig. 

 4i. The free part of 

 these lips is closed with 

 a chitinous skin, thick- 

 est in the middle, un- 

 der which there are the 

 cylindrical epithelial 

 cells, the function of 

 which is to renew suc- 

 cessively the chitinous 

 skin. At the base this 

 skin is exceedingly sub- 

 tile, passing over to the 

 inner coverings of the 

 duplicature. Besides 

 this, we find on each 

 lip, beginning at the 

 top and extending 

 down to the outside, a 

 brush made up of a se- 

 ries of strong bristles 

 extending down. These 

 bristles form a filter, 

 which easily allows the 

 entering oi pollen, but prohibits escape. 

 In the space formed by the free sides of 

 the lip there is the longitudinal muscle by 

 whose contraction the lip is opened; and 

 around the four lips there are the strong 

 circular muscles, wnich easily close the en- 

 trance into this cruciform chasm. The out- 

 ermost layer is a thin chitinous skin, closing 

 the stomach-mouth, and continuing into the 

 inner skin of the honey-sac. In the free 

 sides of the interior of the lips there is a net- 

 work of tracheas, and beyond them the 

 blood-room, the function of which is to nour- 

 ish the muscles and epithelial cells. 



Fig. 3 is a transverse section in the upper 

 fifth of the lips where they are still tree. 

 Fig. 4 shows the sections at different heights. 

 Following the inner skin of the esophagus 

 we find that it goes into the folded skin of 

 the honey-sac, then returns and forms the 

 outer covering of the four lips, at the bot- 

 tom of which it turns again and forms the 

 cross-shaped chasm. At the base the skin 

 becomes exceedingly thin, but is provided 

 with cubical cells and goes into the duplica- 

 ture (Fig. 1, D, also Fig. 7, D). 



The cell-layer of the duplicature descends 

 into the chyle-stomach about ,' of an inch, 

 then turns up and joins closely to the descend- 



THE GENERAL SCHEME OF THE STOMACH-MOUTH OF THE HONEY- 

 BEE IN DIFFERENT SITUATIONS. 



a. a field or swarm bee fasting. 



b. the same eatint^ honey. 



c. a brood-bee eating pollen. 



d. a tarood-bee feeding the brood. 



e. Valvular close from the chyle stomach against the honey-sac, when the 

 first is contracting itself for removing its contents into the small intestine. 



ing part iFig. 1). At this point it ascends 

 and bends around again, passing over rather 

 abruptly into the glandular epithal (cell lay- 

 en of the chyle-stomach. The interior and 

 exterior parts of the duplicature are joined 

 together by fine threads. We will consider 

 the function of these organs later on. 



The most important organ of the whole in- 

 testine is the chyle-stomach. It is a cylin- 

 drical tube with walls that are considerably 

 elastic. The inner covering consists of some 

 layers of cells, the inmost ones being cylin- 

 drical, and the outmost ones cubical. A 

 part of the cylindrical cells reach the glandu- 

 lar organ whose secretion serves for the di- 

 gestion of the food. The ferments of the 

 chyle-stomach, so far as we know, have not 

 yet been examined for the purpose of deter- 

 mining their chemical and physical charac- 

 teristics. A series of the epithelic cells ab- 

 sorb the assimilated food and remove it to 

 the blood, which washes the chyle-stomach. 



On the outside of the epithelic layer we 

 find a great number of circular muscles, 

 which, by their contraction, compress ihe 

 contents and move them against the small 

 intestine or else through the lips outward, as 

 when the bee is feeding a larva. Outside of 

 the circular muscles there are longitudinal 



