INSECT SOCIETIES LAMEERE. 515 



The termites have then for ancestors insects among whom the male 

 as well as the female looks after the offspring, which explains why 

 the male neuters act in the same way as the female neuters in taking 

 the place of the parents in this function. 



It is interesting to note that it is among the very insects which 

 attack wood that is most frequently encountered an association of the 

 two sexes for raising the young. This is notably the case with the 

 hymenoptera of the genus Trypoxylon, as Fabre has shown, and with 

 the coleoptera of the genus Passalus, of which the male and the 

 female eat the wood to nourish their larvae. 



Previously we have shown that the termites are merely specialized 

 Blattidae dating from the tertiary. Now, there exist to-day in North 

 America cockroaches of the genus Dasypoma which live in rotten 

 wood. The females and males are encountered side by side with the 

 young. What more is necessary to arrive at the association of the 

 termites ? First, that the individuals of both sexes occupy themselves 

 with raising their offspring and constitute a family, and then that 

 the first young be neuters and proceed to transform the family into a 

 society. 



Among the social hymenoptera, all of the ants have social habits, 

 while only the higher of the wasps and bees live in associations. 

 Wasps, bees, and ants belong to the group of hymenoptera known as 

 diggers, so remarkable for their habits, but to different classes of 

 diggers. The society is, however, of the same type in these three 

 categories, and in these different cases the origin may be considered 

 as being identical. Among the fossorial hymenoptera the solitary 

 wasps and bees already possess the nest, the basis of every association, 

 a nest built by a fertilized female and formed of cells which the insect 

 fills with provisions for the future larvae. Her task completed, the 

 mother dies without seeing her offspring. In the social types a fer- 

 tilized female begins the construction of the nest and nourishes her 

 first larvae, but her work is far from being done, for very soon the 

 larvae become adults, and these adults, small in size, are neuters of 

 the female sex. The neuters, instead of scattering, help their mother 

 and gratify their own maternal instincts, devoting themselves to 

 bringing up the family. More neuters, all females, come to augment 

 these, and it is only later that are born the males and finally the per- 

 fect females. 



The production of neuters among the hymenoptera has then, as 

 for the termites, transformed a family into a society. 



IV. 



The phenomenon which dominates the origin of insect societies 

 is the appearance of neuters, and we will examine more closely this 



