LITERATURE FOR 1910 ON THE BEHAVIOR OF ANTS, 

 THEIR GUEvSTS AND PARASITES 



WILLIAM MORTON WHEELER 



Bussey Institution, Harvard University 



Brun *^ records a number of observations and experiments on 

 Formica rufa and its subspecies pratensis. Portions of two rufa 

 and two pratensis nests were placed in a bag and, after being 

 dumped in a new locality, formed a single colony without signs 

 of hostility. Nearly two weeks later detachments from the 

 two original ruja nests, one with and the other without brood, 

 were brought ' to the artificially compounded colony. The 

 workers unaccompanied by brood were received with hostility 

 and killed: those with brood were at once amicably adopted. 

 From this and similar experiments Brun infers that the arti- 

 ficial and, to an even greater degree, the natural alliances be- 

 tween members of different rufa colonies are due to a "com- 

 plicated psychically plastic acti\'ity on the one hand, in which 

 the normal instincts are implicated partly by themselves, 

 partly combined with one another, and partly suddenly over- 

 whelmed or surprised ("iiberrumpelt") by powerful engrams; 

 aad on the other hand represent psychic contrast effects and 

 finally even, in many cases, associations of new engrams rapidly 

 combined with one another and with mnemic elements." Brun 

 extended his work to the behavior of riija and pratensis queens 

 introduced into alien nests and to the founding of colonies 

 by these ants. Like Wasmann, he finds that these queens from 

 one colony are readily adopted by the workers, of other colonies, 

 and that this is, under natural conditions, one of the methods 

 of forming new nests or settlements. He also found mixed 

 incipient colonies consisting of rufa and F. fusca var. glebaria 

 and of rufopratensis and fusca similar to those described by 

 Wasmann and Wheeler, showing that new colonies (not new 

 settlements) of rufa and pratensis are formed by temporary 

 parasitism of the queens of these ants on colonies of fusca or 

 of some one of its varieties. 



Burrill ", after studying the trails of the American varieties 

 of the slave-making Formica sanguinea, reaches the conclusion 



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