418 WILLIAM MORTON WHEELER 



Donisthorpe ** records a number of miscellaneous obser- 

 vations on Formica rufopratensis, sanguinea, exsecta, rubescens, 

 Tapinoma erraticum, etc., and on a long list of myrmecophiles 

 found in the nests of these ants. 



Donisthorpe ®^ gives the results of several experiments on 

 the behavior of ants of two species brought together in the 

 same nest; especially the behavior of queens of Formica san- 

 guinea introduced into small colonies of F. fusca or of F. fusco- 

 rufibarhiswiih. pupse, with a view to throwing light on the methods 

 of colony formation. The results obtained with the queens of 

 sanguinea and worker fusca agree closely with those described 

 by Wheeler, Viehmeyer, and Wasmann. The queen attacked the 

 workers and was often killed. In some cases, however, she 

 killed all or nearly all the fusca workers, collected their pupae 

 and stood guard over them. In two experiments the queen 

 became friendly with a few of the surviving workers. In numer- 

 ous experiments with queens of sanguinea and workers of F. 

 fusco-rufibarbis Donisthorpe found that the queens were always 

 killed, usually on the day they were introduced into the nest. 

 This he attributes to the fact that fusco-rufibarbis has a much 

 fiercer and more pugnacious disposition than the typical fusca. 



Emery "', after a survey of , the methods of reproduction 

 in the different groups of social insects, concludes that the 

 " Dzierzon rule, which is valid, with rare exceptions, for the 

 social and for many of the nonsocial Hymenoptera, should be 

 understood as follows: a. The female produces eggs which 

 are pregamically determined as male. b. The male produces 

 spermatozoa determined as female, c. In fecundation the 

 female character of the sperm is dominant. The Hymenoptera 

 that follow Dzierzon's rule are, however, extreme cases, which 

 are certainly connected with the more indifferent cases in in- 

 sects whose ova are pregamically determined as male and fe- 

 male." In connection with these conclusions Emery discusses 

 the extraordinary results obtained many years ago by Fabre 

 in his studies on the determination of the sex of the egg in 

 solitary bees of the genera Osmia and Halictus. 



Emery *' gives a brief survey of polymorphism in the social 

 insects (wasps, bees, ants, and termites). The production of 

 the worker form is held to be the result of inadequate feeding 

 of the larva from which it develops, directly and clearly so in 



