POLYMORPHISM 151 



In some ants, such as the driver ants of Africa ( Typhlopone), 

 the physical differences between the queens and neuters is 

 so great, that even trained entomologists have been misled, 

 and have classed them as entirely different insects. Thus 

 the queen, the male, and the worker of Typhlopone are 

 now known, but until comparatively recently the queen 

 was put in one genus (Dicthadia), the male in another 

 (Dorylus), and the worker in yet another (Typhlopone), and 

 this mistake was made by skilled entomologists, who were 

 misled by the enormous difference in the structure of the 

 three kinds of individual. The male has well-developed 

 eyes, while the worker has none (Fig. 19). 



The polymorphism among social ants and bees has been 

 the subject of much argument, and has produced a great 

 deal of speculation. 1 We are not here concerned with such 

 questions as how polymorphism has arisen. It is sufficient 

 to emphasise the fact that the potentiality of producing the 

 various morphological characters peculiar to the different 

 forms of workers, to the males, and to the queens, must 

 be present in the eggs of the queen, though neither she 

 herself nor any direct ancestor has possessed those that 

 appear regularly in the workers. 



Among the honey ants (Myrmecocystus) some workers 

 are used by the others as reservoirs for honey. These 

 individuals remain in the nest, clinging to the roughened 

 ceilings of certain galleries. In the other galleries the ceil- 

 ings are smooth. They remain in this position for the rest 

 of their lives. Beforehand, they feed on honey for some 

 time, and when they have eaten as much as they can, take 

 up their positions in the nest. Here the other ants feed 



1 Wheeler, W. M., Ants: Their Structure, Development, and Behaviour, 

 New York, Columbia University Press, 1910 ; Escherich, K., Die Ameise. Schil- 

 derung ihrcr Lebensweise, Braunschweig, Fr. Vieweg und Sohn, 1906 ; Ihering, 

 H. von, " Zur Frage nach dem Ursprung der Staatenbildung bei den sozialen 

 Hymenopteren," Zool. Anz., xxvii., 4, 1903 ; Herbst, C., Formative Reize in der 

 Tierischen Ontogenese, Leipzig, Arthur Georgi, 1901 ; Silvestri, F., " Contri- 

 buzioni alia conoscenza dei Mirmeconli, Ann. Mus. Zool. Univ. Napoli, i. 13, 

 1903. 



