APHIS HERDS AND ANT ASSOCIATES 



stealthy method of these marauding mites is not cal- 

 culated to arouse the ire of the Formicas and marshal 

 them for resistance, as would, for example, the raid of a 

 battalion of slave-makers. They have the real kleptic 

 faculty of human robbers, and steal softly to their work. 

 Having acquired the protective nest-odor of their host, 

 they doubtless pass in and out, not unchallenged, but with 

 impunity. In America, Solenopsis fugax is represented by 

 S. molesta, a minute yellow ant with yellow queens and 

 dark-brown males. It is widely distributed, and Professor 

 Wheeler thinks that its habits are substantially the same 

 as those of its European congener. [W. 1, p. 533.] 



It remains to speak of that form of consociation whicji 

 Wheeler has classified as Plesiobiosis, the "double nests " 

 of Forel, and which Wasmann has designated as acci- 

 dental forms of compound nests. This comprises cases 

 in which two, or rarely more, colonies of ants of different 

 species occupy galleries and seemingly have established 

 formicaries in close contact. 



Among these ants Professor Wheeler groups several 

 species observed by this author. The foetid ant (Fore- 

 lius fcetidus Buckley---? 7 , maccooki Forel) is a small, 

 yellowish dolichoderine ant which lives amicably with- 

 in the nest boundaries of the Texan agricultural ant. 

 Numbers of these ants were seen frequently travelling 

 in long lines, in single or " Indian" file, across or near the 

 nests of the agriculturals. Usually their route was upon 

 blades of grass growing on those nests that were covered 

 with needle-grass (Aristida) , or along low tufts of grass 

 on the margin of the disk. The agriculturals took no 

 notice of their tiny neighbors at least, never interfered 

 with them- -and the two species seemed to be upon 

 the most friendly terms with each other. [McC. 3, p. 202.] 



257 



