BEHAVIOR OF ANTS AND MYRMECOPHILES 433 



but does lean toward his theory that the social parasitic stages 

 were derived from a n//a-like form. 



Brim (3) believes that the theoiy of the mixture of odors, 

 which has been used to explain, in a purely physiological way, 

 the tolerance of one species toward another in the artificial 

 alliances of certain species of ants, must be given up, as entirely 

 untenable. These artificial alliances do not depend upon the 

 mixture of odor, but depend entirely upon complex associative 

 brain processes, especially in the realm of individually acquired 

 mnemic engrammes. 



Cornetz (5) believes that the apparent cooperation of several 

 ants in moving particles of food too large to be handled by a 

 single individual is simply the result of the stimulus that causes 

 the solitary ant to return home. When an ant starts on a forag- 

 ing trip it receives, in some manner, an impression that later 

 guides it back to the nest. When it finds a morsel of food it 

 takes it, and returns by an almost direct route. Several ants, 

 having hold of a morsel too large for a single one, are each 

 guided by this direction-sense toward the nest, with the result 

 that the combined efforts of many holding and pulling the 

 piece of food are used to bear it. This gives at first sight the 

 impression of mutual aid, but is in reality only "a fortuitous 

 coincidence of purely individual actions." There is even actual 

 hindrance to one another when many have hold of the same 

 morsel. Likewise, other actions at first sight mutualistic are 

 believed to be simply the result of individual activity 01 of a 

 certain tendency toward imitation, comparable to the flocking 

 of sheep. Thus, Cornetz saw an isolated worker digging at a 

 new nest some distance away from the principal nest. In another 

 instance seven workers were engaged in working at a gallery far 

 from the nest. These carried eggs, larvae and even adults from 

 the original formicary, in which, however, most of the colony 

 remained. This division was in no sense beneficial to the entire 

 community, but was probably the result of several workers fol- 

 lowing one that had started the new gallery. As the worker is 

 merely an undeveloped female, the tendency to establish a new 

 colony is not surprising, as often other female characters are 

 more or less developed in individual workers, even parthogenetic 

 reproduction, and the nest-forming habit is typically female. 

 When one worker begins to dig a new nest, others cooperate 



