340 ENTOMOLOGY 



workers may be seen, one composed of individuals returning 

 to the nest, each with a piece of a pine needle, the other of 

 outgoing workers. The nest is a simple structure, extending 

 some seven inches underground and ending in a chamber in 

 which are several small pulpy balls, consisting probably of 

 masticated leaves. Further studies upon our own leaf-cutting 

 ants, modeled after the admirable studies of Moller, are much 

 to be desired. 



Harvesting Ants. Lubbock observes that some ants col- 

 lect the seeds of violets and grasses and preserve them care- 

 fully for some purpose as yet unknown. From such a begin- 

 ning as this may have arisen the extraordinary habits of the 

 agricultural, or harvesting, ants, of which some twenty species 

 are known from various parts of the world. 



The Texas species Pogonomyrmex barbatus, studied by 

 Lincecum and by McCook, clears away the herbage around its 

 nest (even plants several feet high and as thick as a man's 

 thumb) and levels the ground, forming a disk often 10 or 12 

 and sometimes 15 to 20 feet in diameter, from which radiating 

 paths are made, from 60 to 300 feet in length. The ants go 

 back and forth along these roads, carrying to the nest seeds 

 which they have collected from the ground or else have cut 

 from plants ; these seeds are stored in " granaries " several feet 

 underground and are eventually used as food. The ants pre- 

 fer the seeds of a grass, Aristida oligantha, but the oft-repeated 

 statement that they sow the seeds of this " ant-rice," guard it 

 and weed it, is denied by Wheeler. 



Notwithstanding the elaborate studies of McCook upon this 

 subject, there still remain not a few essential questions to be 

 answered. 



Myrmecophilism. To add to the complexity of ant-life, 

 the nests of ants, when at all extensive, are frequented by a 

 great variety of other arthropods, which on account of their 

 association with ants are termed myrmecophiles. Most of 

 these are insects, of which Wasmann has catalogued 1,200 

 species, but not a few are spiders, mites, crustaceans, etc. 



