60 Heredity. 



Although these cases make a long list, which might 

 be greatly increased, they are still exceptional, for in all 

 tliese species almost all the eggs fail to develop unless 

 they are fertilized by a male; but in some other groups 

 of insects parthenogenesis occurs more frequently, and 

 seems to be perfectly normal. The most remarkable in- 

 stances are those which occur in the social insects, such 

 as the bees. 



It is well known that a community of honey-bees con- 

 sists of individuals of three kinds — the workers or ru- 

 dimentary females, which are the most numerous; the 

 perfect females or queens, of which only one is usually 

 present in a hive; and the drones or males. 



In the workers, or as they are sometimes falsely called 

 the neuter bees, the female reproductive organs are very 

 imperfectly developed: the vagina is so small that union 

 with a male is hai'dly possible, and the receptaculum- 

 seminis is very rudimentary, yet it is well known to all 

 bee-cultivators that they do sometimes lay eggs which 

 are capable of development, not only in the honey-bee 

 but in other species also. Among the honey-bees such 

 fertile workers are alwavs found in a hive which has lost 

 its queen, and they have been called '* drone mothers," 

 from the fact that their eggs produce only drones or 

 males. 



The queen-bee is the only member of the hive which 

 unites sexually with the males, and her reproductive 

 organs are very large and well developed, as contrasted 

 with those of the worker. Her receptaculum seminis is 

 large enough to retain a sufficient supply of the male 

 fluid to serve for fertilizing great numbers of eggs, and 

 it is usually found to contain a considerable quantity. 

 Sexual union takes place during flight, and queens with 

 imperfect wings are never impregnated, and Siebold, 



