230 THE BIOLOGY OF INSECTS 



1,500,000 eggs during her life. As mentioned previously 

 (Chap. VI), female Ilymenoptera are developed normally 

 from fertilised and males from unfertilised eggs, and it is 

 well established that the growth of a bee-grub hatched from 

 a fertilised egg either into a queen or into a worker depends 

 on the nature of its food. Larvae destined to become queens 

 are reared in large ovoid *' queen-cells " situated at the edge 

 of the comb, and fed throughout their growth with " royal 

 jelly," believed to be a secretion of the worker's pharyngeal 

 glands. Worker-grubs, on the other hand, receive this 

 food only for the first four days of their development after 

 hatching ; during the final two days of larval life they are 

 fed by the workers on honey and pollen. The food of the 

 queen-larvae is relatively very rich in fat, that of the worker- 

 larvae in sugar. That the kind of female developed from a 

 fertilised egg is determined by feeding has been often proved 

 experimentally by transferring very young grubs from one 

 kind of chamber to the other. The male bees are developed 

 from unfertilised eggs which the queen lays in '' drone- 

 cells " of hexagonal shape like the worker-cells but of larger 

 size ; when laying these the queen-bee releases no 

 spermatozoa from her sperm reservoir, as she does when 

 laying in cells provided for the rearing of female bees. This 

 is doubtless the general mode of procedure, but reasons 

 have already been given (p. 140) for allowing the possibility 

 of the exceptional origin of male bees from fertilised and 

 of females from unfertilised eggs. 



Besides the '' brood-comb " in which the grubs are reared 

 many series of chambers form a '' honeycomb " for the 

 storage of food. It is from this store that the grubs are 

 supplied, and it has long been known that the first period of 

 a worker-bee's life after emergence from the pupal coat, 

 is spent within the hive, and that expeditions for the gather- 

 ing of nectar and pollen are not undertaken until she has 

 attained a certain age. It has been recently stated by 

 G. Roesch and K. von Frisch (1925) that there is a routine 

 of duties through which all the workers of a hive succes- 

 sively pass. The first work of a newly emerged bee is to 



