GLAND STRUCTURES. Si 



with the largest ovaries have even the plate im- 

 perforate, while no trace of duct is discoverable, just 

 as in the case of the drone plate (C). But taking 

 a queen Bombus (page 13), engaged in establishing 

 a nest, when she does feed her own brood, we find 

 this particular gland strongly developed ; whilst in 

 other bees, such as the mother Megachile centun- 

 cularis (page 9), which secretes no wax, but raises 

 her own young, we still see it, though of smaller 

 form. We thus get some evidence that rendering 

 wax plastic is not the duty of this gland, but that 

 the feeding of brood is. Again, examining a young 

 worker employed in nursing, we find this gland 

 turgid, and in the highest state of activity ; while in 

 the old bees of a broodless stock it is much 

 shrunken, at the same time that glands No. 2 and 

 No. 4 retain their normal size. Coupling this fact 

 with the larger dimensions of No. 2* and No. 4 in 

 the queen, and remembering her need of assimilation 

 in order that her eggs may be produced, we shall not 

 be far wrong in ascribing to No. 2 and No. 4 a diges- 

 tive function. In other words, they are truly salivary 

 in character, which position is further supported by the 

 existence of these glands in less development in the 

 drone. But to return ; microscopical examination of 

 the food given to very young larvae reveals no trace of 

 a pollen grain, and shows that it resembles in nothing 

 any part of the contents of the chyle stomach of the 

 nurses. It is, on the contrary, just such a fluid as a 



* Siebold, followed by Girard, says that No. 2 is small in the queen; 

 but this is clearly an error. In many scores of queens dissected, I have 

 uniformly found it larger than in the worker, and often containing sacules 



H 



