LONGEVITY OF TERMOPSIS. 1 63 



that the workers live about four years after their final molt, arid 

 it is probable that this completed state is reached during a period 

 of at least one year, so their life is terminated at the end of about 

 five years. 



The soldiers I have been unable to keep, in a great majority of 

 cases, more than three years in a fully developed condition. In 

 a few colonies I have kept them more than four years, and in the 

 nest in the hermetically sealed jar two soldiers lived to be nearly 

 five years of age. Generally speaking the average life of the 

 soldier is about four years from the time of hatching. 



While making these observations concerning the formation of 

 the colony and its subsequent development, I have conducted a 

 number of experiments to discover if possible the mode of forma- 

 tion of the various castes. A careful examination of the eggs 

 and the newly hatched young fails to disclose differences which 

 appear to be correlated in any way whatsoever with those dis- 

 tinguishing the soldier, worker and perfect insect to which they 

 give rise. Grassi and Sandias, 1 and others with whom I agree, 

 are of the opinion that it is a question of nutrition ; that the royal 

 pair or the workers by judicious feeding direct the course of devel- 

 opment along particular lines. I believe that theoretically all of 

 the young are destined to become perfect insects, but in many 

 cases their growth is arrested or modified and complemental 

 royal forms or soldiers or workers result. Under certain cir- 

 cumstances the modification is not perfect and monstrous forms 

 result, such as soldiers with wings and the ability to produce 

 eggs which may develop. In the examination of many hundreds 

 of colonies formed originally under natural conditions I have 

 found a few such monstrosities, and the surroundings invariably 

 suggest that they have developed under unnatural conditions. 

 In most cases they have appeared in small fragments of wood, 

 which have broken off from the main trunk inhabited by an ex- 

 tensive colony invariably headed by complemental royal forms. 

 With the separation of a small portion of a community changed 

 conditions must arise. New complemental royal forms and in cer- 

 tain cases additional soldiers have to be produced, and it is reason- 

 able to suppose that the enlargement of the nest and the care of the 

 eggs and the developing young demand a profound readjustment 



1 " Costituzione e Sviluppo della Societa dei Termitidi," Catania, 1893, 150 pp. 



