CEsophagus of Worker Bee. 117 



Dr. Planta and others have shown that the chyle fed to 

 <]ueen larvae is not the same as that fed to drone larvae, nor 

 ytX. like that fed to worker larvae. If this is chyle the dif- 

 ference could be explained, as it would arise from variation 

 •of food. If a secretion, it could not be easily explained. 

 This view is adopted by Mr. Cowan the ablest and most 

 learned British authority on bees. 



As in our own development, so in the embryo bee, the 

 alimentary canal arises from the endoderm or inner layer 

 of the initial animal. As the ectoderm or outer layer is 

 around this, the mouth and vent arise by absorption at these 

 points, or from invagination (a turning in) of the outer 

 layer. Infants are not infrequently born with an imper- 

 ■forate anus. In such cases there is an arrest, the absorp- 

 tion does not take place, and the surgeon's knife comes to 

 nature's relief. Strangely enough in the bee— this is also true 

 of ants and some wasps — this condition persists all through 

 the larval period. Thus bee larvae have no anus or vent, 

 and so void no excreta. But as known both to Swammer- 

 ■dam and Newport, when the last larval skin is molted the 

 whole canal, with its contents, is molted with the skin. As 

 already stated the spinning glands in the larva become the 

 thoracic, or glands of Ramdohr, in the adult bee. 



The oesophagus or gullet, the fine thread which is pulled 

 •out as we behead a bee, passes from the mouth through 

 ■the muscular thorax (Figs. 15 and 21 ) to the honey-stomach 

 (often called sucking stomach), which is situated in the 

 abdomen. Often, as every bee-keeper knows, this honey- 

 -stomach (Fig. 21, A, f) comes along with the oesophagus as 

 we pull the bee's head from the body. The oesophagus 

 {Fig. 21, o) is about .2 of an inch long and .02 of an inch 

 in diameter. In form and function the oesophagus is not 

 •different from the same organ in other animals. It is 

 simply a passage way for the food. 



The honey stomach (Fig. 21, ^ j) or honey sac is a sort of a 

 <;rop or proventriculus. This sac is oval about .1 of an inch 

 in diameter. While this organ is lined with a cellular layer 

 {Fig. 40, H, 6", ^), the cells are not large and numerous 

 as in the true stomach (Fig. 40, S,E^. The muscular 

 layers of this sac ai'e quite pronounced (Fig. 40, »?) as we 



