v SOCIAL HOMES 183 



easily recognisable. Slight and perishable as they 

 appear, the rain may fall in torrents without wetting 

 them. Over the whole the wasp lays a thick coating 

 of a blackish but transparent varnish, which renders 

 them waterproof ; it also binds the group firmly 

 together, and gives it a high polish. The small 

 dimensions of the nest lead one to think that these 

 wasps form societies of a different nature from those 

 of immensely populous communities: Towards its 

 basal end the cells become small, a diminution that 

 arises simply from the fact that they are yet incom- 

 plete ; originally the upper cells were in the same 

 unfinished state. It is incorrect, though very natural, 

 to suppose that the higher and larger compartments 

 are for the future males and females, the lower and 

 smaller ones for the breeding of the workers. The 

 similarity of completed cells raises important ques- 

 tions. Are these societies true societies, do the males 

 and females belong to the same brood, are they of 

 like size, and nurtured in the same cells ? Possibly 

 the sexes are reared in separate establishments, on 

 the principle of unisexual or dioecious* plants. 



Not the least extraordinary of the wasps are the 

 Icarias, a genus that extends through most of the 

 warmer regions of the world, specimens having been 

 taken in Africa, India, China and Australia, and in 

 many parts of the Asiatic Archipelago. Like the 

 Polistes, their nests are attached to leaves, stalks, or 

 branches by a single footstalk, composed of the same 

 papery material as the cells. Though slender it is 

 hard, tough and solid, and the strength with which it 

 is fastened to the tree or plant is surprising, enabling 



