1906.] Wheeler, Founding of Colonies by Queen Ants. lOl 



like that of F. consocians, truncicola, etc. Dulosis is rather to be re- 

 garded as a distinct manifestation, which has probably arisen independ- 

 ently from the same basis as temporary social parasitism. This basis, 

 as we have seen, is the instinct to form polydomous colonies, like those 

 of rufa, exsectoides, etc., by adopting females of the same species and 

 multiplying nests. Wasmann has shown that the European san- 

 guinea is very prone to proliferate over several nests. This seems to 

 be true also of some of our American varieties and subspecies, although 

 I have seen indications of it only in certain localities. Wherever it 

 occurs it may be taken to indicate that some of the females after fe- 

 cundation either remain in or return to colonies of the parental species. 

 In founding new colonies, however, the females obey the same instinct 

 which impels them to return to the parental nest, namely to enter 

 colonies in which they find the already familiar fusca workers. To 

 this extent, and, I believe, no further, have dulosis and temporary 

 social parasitism a common phylogenetic origin. 



Now if we regard the worker instincts as derived from those of the 

 queen, instead of as activities sui generis, the matter will appear in a 

 clearer light. The dulotic tendencies of the worker are then referable 

 to the instincts which the female has occasion to display only while 

 she is founding her colony. The differences are largely due to the fact 

 that the workers make their forays not singly and but once in their 

 lives but in companies and repeatedly and on populous fusca colonies 

 which the females could not enter. Wasmann has explained the fact 

 that the workers select the fusca colonies as the objects of their raids 

 because this species happens to be a very familiar one, since it reared 

 them in the parental nest. This is probably true, but it is even more 

 evident in the case of the queen, since the tendency to invade such a 

 nest is in her reinforced by the traditional purpose of establishing a 

 colony. 



Pursuing the matter still further, however, we come to deeper 

 and more general instincts. At first sight the catenary reflexes man- 

 ifested by the ruhicunda in the experiments recorded on pp. 75 to 83 

 appear to be very unusual and quite in harmony with the unique and 

 exceptional character commonly attributed to dulosis. It is probable, 

 however, that young and vigorous females of nearly all species of ants, 

 when confronted with a small number of hostile workers and their 

 brood, either of the same or of an alien species, would behave very much 

 like the queens of ruhicunda : they would, in other words, slaughter the 

 workers and take possession of the brood. The attacks of the workers 

 would naturally goad the queen to self-defence and violence while the 



