352 Experimental Zoology 



the worker cells that are very numerous; the drone cells that 

 are much fewer in number; and the royal cells, of which there 

 are, as a rule, only a very few. It has been shown both by di- 

 rect observation and by experiment that the eggs laid in worker 

 cells and in the royal cells are fertilized. These eggs produce 

 females only. In the worker, the female sexual organs never fully 

 develop. The eggs laid in the drone cells are unfertilized, and 

 give rise to. the drones or males. Rarely a queen may make 

 a mistake and lay a fertilized egg in a drone cell, where it be- 

 comes a worker; or lay a drone egg in a worker cell, where it 

 becomes a drone. Evidently, then, the sex is not determined by 

 the character of the cell, but by the presence or absence of the 

 spermatozoon. 



A worker egg can be changed into a queen if the young larva 

 is supplied with the food given to the young queens. This can 

 be accomplished artificially by placing some of the royal jelly 

 taken from a royal cell (where it exists in excess) in a worker cell, 

 containing a young maggot not more than a day or two old. The 

 bees will then continue to supply this cell with the royal jelly, and 

 will break down the neighboring cells, destroying their inmates 

 and thus make a larger, royal cell around this nouveau riche 

 member of royalty. A drone egg cannot be changed into a 

 worker or into a queen, although an exceptionally large male 

 may be produced by feeding on the royal nutriment. 



When a queen has become old and has used up all of the sperm 

 in the spermatheca, she can produce only drone bees. Also 

 when a young queen is prevented from leaving the hive she 

 produces only drones ; for it appears that union with the males 

 cannot take place within the hive. Workers also have been 

 known at times to lay eggs which produce only drones. These 

 and other facts led Dzierzon, in 1845, to formulate his famous 

 theory. The substance of his view has already been given. He 

 stated that a queen must be fecundated if she is to produce 

 new queens and .workers ; that drone eggs are not fertilized ; but 

 that worker eggs and queen eggs are always fertilized. Dzier- 

 zon also discovered that during copulation the eggs in the ovary 



