n6 Function of Glands of Siebold. 



Wolff's glands are large follicular glands (Fig. 39) situ- 

 ated at the base of the mandibles. From their position we 

 might suppose that their secretion was useful in forming 

 wax into comb, but their large size in the queens, would 

 rather argue that they, like the racemose glands, were also 

 digestive in their function. I would suggest that we call 

 the thoracic glands, the glands of Ramdohr; the racemose 

 glands of the head, the glands of Meckel, and the other 

 glands of the head glands of Siebold, in compliment to the 

 excellent work which he has done in their study and elu- 

 cidation. While the glands at the base of the mandibles- 

 may well be called from their discoverer, Wolff's glands. 

 In studying the digestive organism we are greatly indebted 

 to Schiemenz and Schonfeld, who have not only explained 

 by use of beautiful illustrations the detailed anatomy of the 

 alimentary canal, but have been equally happy in describ- 

 ing the wonderful physiology of digestion in bees. Schon- 

 feld from a very elaborate series of experiments concludes 

 that the theory of Schiemenz and v. Siebold is not correct. 

 He thinks the lower head glands secrete saliva which 

 moistens the pollen, and aids in digesting it. They empty 

 on the floor of the mouth just where they should pour out 

 the saliva. As the queen and drones never eat pollen, but 

 are fed by the workers they do not need these glands. 

 Schonfeld thinks the larval food is digested pollen or chyle, 

 and he claims to have found this in the true stomach of 

 nurse bees. Partially digested pollen he terms chyme, which 

 just before the worker larvse are to be sealed up, is fed to 

 them. The chyle and larval food he finds to contain blood 

 corpuscles, and he thinks them identical with the same irv 

 the blood of the bee. Schonfeld fed indigestible material 

 like iron particles to starving bees that had brood. The 

 chyle, the larval food, but not the blood of the nurse bees 

 contained this iron. This food of the larvae then must be 

 chyle and not a secretion. This experiment seems con- 

 clusive. 



Again these same lower head glands are found in some 

 insects that do not feed their larvse at all, as species of Eris- 

 talis — ^wasp colored two winged flies — and of Nepa, a genus, 

 of water bugs. 



