• INSECT COMMUNITIES 299 



This the ants consume, having first arrested further growth 

 by nipping off the young shoots. 



The allied Texas species (Pogonomyrmcx barbalus) is 

 even more advanced in its methods. Paths from 60 to 

 800 feet in length radiate from the nest, and along these 

 the insects go to and fro to gather their harvest. When 

 the seeds are safely garnered, their husks are removed by 

 the ants, and placed on a kind of midden outside the nest. 

 Furthermore, the ants clear away all the herbage in the 

 immediate vicinity of their nests, or formicaries, with the 

 exception of two species of grass (Aristida oligantha and 

 A. strict a) known as " ant rice." The seeds of these 

 grasses are especialty liked by the ants, and there is no 

 room for doubt that they cherish the plants on this 

 account. Dr. H. C. McCook states that : " No other 

 plant is thus tolerated, and these seeds are gathered and 

 stored with others in the underground granaries. More- 

 over, it is quite within the ants' power to keep their discs 

 clean. They were often found established in a thicket 

 of wild sage, daisy, and other vigorous weeds, with stalks 

 as thick as one's thumb and standing several feet high. 

 This rank growth, quickened by the fat soil and semi- 

 tropical sun, is as thoroughly under the control of our 

 Barbati as are the cleared fields amid the woods under the 

 settlers' control. Not a plant is allowed to intrude upon 

 the formicary bounds ; and although often seen, it was an 

 interesting sight, after pushing through the high weeds, 

 to come upon one of these nests, and observe the tall, 

 tough vegetation standing in a well-nigh perfect circle 

 around the edge of the clearing. The weeds had crowded 

 up as closely as they dared, and were held back from the 

 forbidden ground by the insects, whose energy and skill 

 could easily limit their bounds. Certainly, ants capable 

 of such work could readily have cleared away growing 



