THE ALIMENTAEY CANAL AND ITS GLANDS. 95 



principal function in the bee is to hold the nectar as it is collected 

 from the flowers and to allow the worker to accumulate a consider- 

 able quantity of this liquid before going back to the hive. Hence, 

 since the honey stomach is a sac with very distensible walls, its 

 apparent size varies greatly. When empty it is a small flabby pouch, 

 but when full it is ah enormous balloon-shaped bag with thin tense 

 walls. The histological structure of the honey stomach (fig. 4.5, HS) 

 is exactly the same as that of the oesophagus. The numerous high 

 folds into which its epithelium (Epth) is thrown permit the enor- 

 mous expansion of which the sac is capable. When a worker with 

 its honey stomach filled with nectar reaches the hive, the nectar is 

 either stored directly in a cell or is given up first to some other 

 worker, who places it in a cell. 



It would appear that all the food swallowed by a bee must go first 

 into the honey stomach, and since the bee's diet consists of pollen and 

 honey as well as nectar, one would suppose that in regurgitating the 

 latter the bee would also disgorge the pollen it might have recently 

 eaten. Honey which is made from the regurgitated nectar does 

 indeed contain some pollen, but most of the pollen eaten by the bee 

 is undoubtedly retained in the stomach as food. The apparatus by 

 means of which the pollen is supposed to be separated from the nec- 

 tar belongs to the following division of the alimentary canal, but it 

 is not known that the worker takes nectar, and pollen for food, into 

 its honey stomach at the same time. 



The proventriculus (figs. -±2 and 44, Pvent) forms the necklike stalk 

 between the honey stomach [HS) and the true stomach or ventricu- 

 lus {Vent), but a very important part of it also projects up into the 

 honey stomach (fig. 44 C). If the honey stomach be slit open, a 

 short, thick, cylindrical object will be seen invaginated into its pos- 

 terior end and having an X-shaped opening at its summit (fig. 44 C, 

 nn). This opening is the mouth of the proventriculus, and its four 

 triangular lips, which are thick and strong, mark four longitudinal 

 ridges of the proventricular tube. This structure is commonly known 

 as the " stomach-mouth " and is supposed to be an apparatus de- 

 signed especially to enable the worker to pick out pollen grains from 

 the honey stomach and swallow them on down into the true stomach 

 or ventriculus, while the -nectar is left to be stored in the hive. 

 Cheshire says : " While the little gatherer is flying from flower to 

 flower her stomach-mouth is busy separating pollen from nectar." 

 This notion is so prevalent among bee writers in general that it 

 passes for a known truth. Yet it has really never been shown that 

 the worker eats pollen while she is gathering nectar. Probably no 

 more pollen is ever mixed with the nectar in the honey stomach than 

 is found in the honey itself. Furthermore, under normal conditions 

 pollen never accumulates in the honey stomach, even when the bee 



