22 Riley — Presidential Address. 



by the indignant workers, the male wasji is respected and pro- 

 tected, and dies a natural death. In the large nests of hornets, 

 the number of males and perfect females produced in the autumn 

 amounts to several hundred, and of these comparatively few 

 females successfully hibernate. Were it otherwise ordained, these 

 insects would become too numerous for the comfort of the rest 

 of the world. 



The larvffi are fed from day to day with a prepared liquid food 

 which is disgorged from stomachs of the adults. These 

 prey upon other insects, and also feed upon animal or vegetable 

 matter to which they have access, and are particularly fond of the 

 sweets of fruits, melons, etc., also of sugars and honey, all of 

 which are eaten greedily, and commingled ami prepared in the 

 stomach as food for the young. Wasps are not particularly active 

 themselves in the collection of honey from flowers, but are very 

 prone to rob the hives of bees whenever opportunity offers. 



We have seen that in the case of the Hive Bee the unfertilized 

 egg, including the egg deposited by the worker bee, invariably 

 produces a drone or male. The experience of English observers, 

 indicates that the reverse of this is true of the social wasps, 

 and that, instead of males being produced from eggs of workers 

 or non-fertilized wasps, other workers similar to the parent are 

 produced. Thus from nests from which the queen wasp is 

 removed quite early in the spring, the generation of workej's 

 continues through the season as freely as if the queen were still 

 present to lay eggs, showing that the brood is kept up by the 

 progeny of workers having no access to males, which only appear 

 in the fall. Leuckart has also shown, by careful dissections, that 

 nearly fifty per cent, of the worker generations in the latter part 

 of the summer at least, have fully developed and develojoing eggs 

 in their ovaries. 



It must be noted, however, that the experience of Von Siebold 

 with Polistes gallica directly contradicts the observations of Eng- 

 lish investigators. His experiments carried on in precisely the 

 same way, indicate that, with this species at least, the eggs from 

 the workers produce males. There would, therefore, seem to be 

 no unifofmity in this regard among the different species of the 

 family, both arrenotoky and thelytoky ocouring among them, and 

 possibly in the same species at different seasons. 



In the case of Vespa there is no difficulty in separating the 



