ORIGIN OF CASTES OF TERMITES 97 



from the sex organs may be the cause of the differentiation of the 

 worker caste, and adds that this view has alreadj^ been advanced 

 by O. Hertwig ('98). 



Forel ('04) in a dehghtfully broad analysis of the subject of 

 polymorphism and variation in ants, remarks upon the authority 

 that ma}' cling to a formerly widely accepted dogma. He cites 

 the recent work of Janet and ^Mieeler as evidence against the 

 hypothesis of qualitative feeding as a factor in caste production. 



Aber auch mit der kiinstlichen Emahrung zu verschiedenen poh'- 

 morphen Formen, an welcher Prof. Emer\' fest hielt, habe ich mich 

 aus verschiedenen Gnmden nie befreunden konnen. Wie konnte die 

 verschiedene Quantitat der Xahrimg 3 so verschiedene Formen wie 

 Weibchen, Soldat und Arbeit er hervorrufen? 



Von Ihering ('03) in a study of the stingless bees of Brazil 

 shows that in the genus ]\Ielipona the brood cells are all of equal 

 size. The same kind of food, honey and pollen, is placed in 

 each cell, an egg is laid in each, and the cells are then sealed up. 

 From these similar cells, containing similar food, the three well 

 defined castes emerge. The queen of ^Nlelipona hatches with 

 small immature eggs in her ovaries. 



In the genus Trigona, the queens hatch from large brood 

 cells which project beyond the edge of the comb and contain a 

 large store of honey and pollen; the drones and workers emerge 

 from smaller cells. The queen of Trigona hatches with large 

 ripe eggs ready to lay. The conclusion is that the larger queen 

 cells and the greater amount of food are only the means of hasten- 

 ing the development of the sex organs, and not the factor that 

 produces a queen. "\Mieeler ('07) suggests, in commenting upon 

 von Ihering's observations, that the 'royal jelly' fed to the queen 

 larva of the honey bee is ''merely an adaptation for accelerating 

 the development of the ovaries," since the queen honey bee 

 hatches in about sixteen days and with nearly ripe eggs in the 

 ovaries, while the worker requires four or five days longer f'^r 

 her development. "If this interpretation is correct the qualita- 

 tative feeding of the queen larva is not primarily a morphogenic 

 but a growth stimulus." It is disappointing that Xelson ('15) 

 does not discuss this question in his ''Embryology of the Honey 

 Bee." 



JOCRNAL OF MORPHOLOGY, VOL. 30, N'O. 1 



