THI- HARVESTING ANTS. 



279 



far north as Xevv Jersey and New York, have similar habits. I have 

 found a considerable number of harvesters among the species of the 

 dry deserts of Colorado, Texas, New Mexico, Arizona and Mexico (Ph. 

 colonnicnsis, instabilis, ceres, sitarclies. soritis. I'ashtti, carbonaria, 

 etc.). Though far more peaceable, these ants often resemble S. ycini- 

 nata in their nesting habits. Some of them at least (Ph. instabilis, 

 siturchcs) are certainly unable to prevent the germination of seeds in 

 their granaries during the wet weather. I infer, therefore, that they 

 do not bite off the radicle as has been claimed for the European Messor 

 and the Australian Phcidole. The large-headed soldiers of the numer- 



FIG. 159. Disk of Pogonotnyrmc.v nigosus in the Arizona desert. (Original.) 



ous carnivorous species of Phcidole function as trenchers and carve 

 the tough insects brought into the nest by the small, feeble workers, and 

 thus make the soft tissues accessible to the community. Among the 

 seed-storing species, however, the soldiers have become the official nut- 

 crackers of the colony. I have seen the workers of some of the species 

 ( instabili's and sitarclies ) feeding the larvae directly with pieces of 

 crushed seeds. 



More striking are the habits of our largest harvesters belonging to 

 the genera Messor, Ischnomyrmcx and Pogonowiyrvnex. With the 



