HO ROMANCE OF THE INSECT WORLD CHAP. 



two and a half inches, diverges into tubular galleries 

 connected with the granaries and nurseries. In 

 general these rooms are circular, oval, and crescent- 

 shaped. The depth to which they are carried prob- 

 ably varies, but nests have been excavated as far as 

 four feet below the surface and no termination of the 

 mining was reached. Rooms even at two and a half 

 feet down are packed with seed, and narrow gang- 

 ways are left at the outer margin between the grain- 

 heaps and the wall. The elevations upon the disks are 

 used for habitation, and are not simple accumulations 

 of earth excavated from the underground cells and 

 galleries. The architecture of the Florida harvester 

 (P. crndelis] is in close resemblance to the cone 

 structures of the Texan agriculturist. 



The nests of the other known North American 

 congener of Pogonomyrmex, the Occident Ant of 

 the great American plains (P. occidentalis\ are similar 

 in exterior to the gravel-covered cones of the Texas 

 and Florida harvesters. They form conspicuous 

 objects upon the level plains, or gently sloping hills, 

 alike by their elevation and their great numbers. The 

 cone rises to a height rarely exceeding ten inches, 

 though it appears much more, owing partly to the 

 situation. It generally stands in or near the centre of 

 a round or elliptical pavement or clearing, but no crop 

 of " rice " breaks its monotony ; it is always totally 

 freed of vegetation, unless it be for an occasional tuft 

 or blade of grass straggling here and there. Its use 

 then differs from that to which the Texan nest-space 

 is put, since it is no harvest-field. Its advantages, 

 however, are manifest. By it the ants gain easy 



