394 Bulletin American Museum of Natural History. [Vol. XXI, 



of host, guardian, and nurse to the corn root aphis; viz., Formica 

 fusca, Formica schaufussi, Lasius niger, Lasius niger alienus, Lasius 

 interjectus, Myrmica scabrinodis , and Solenopsis dehilis. The occur- 

 rence in this relation of all but the third and fourth just mentioned is, 

 however, so rare that they need receive here no more than this passing 

 mention, especially as their services to the aphis are, so far as ob- 

 served, the same in character and value as those of the much more 

 abundant species." 



The following notes are given on the life-history, haunts, actions, 

 and habits of the ant: 



"The winged sexual forms, male and female, of this ant begin to 

 appear each year, as early as the latter part of June (the 21st to the 

 27th), hatching from pupae which may have formed late in May (27th 

 and 28th, by our notes). The emergence of males and females from 

 the pupae continues throughout the season, certainly into October 

 and probably to November, but the males perish before the winter. 

 The females, however, having been fertilized and deprived of their 

 wings, begin their separate excavations in fall, or continue with the 

 workers in nests already established. There they hibernate, some- 

 times, at least, commencing to lay their eggs in fall and living in 

 spring through April and May. 



" The nests or burrows of this ant, in which these breeding opera- 

 tions are carried forward, are widely distributed in corn fields and 

 grass lands, — especially in the latter, along the borders of roads and 

 paths, — and also under stones and boards, in and under decaying 

 logs, and in an indefinite variety of situations. In corn fields they 

 are established almost wholly in the hills of corn, and remain here 

 among the old corn roots throughout the season. As this is the 

 commonest and most generally distributed of all our ants in Illinois, 

 an exhaustive list of its places of habitation would have little present 

 interest. It has never been -found by us to form large settlements, 

 or making mounds or conspicuous structures of any kind; but simply 

 scattering its little burrows almost indiscriminately, living in small 

 families rather than great colonies or city-like aggregations, and 

 piling up only a small temporary heap of pellets around the mouth 

 of its burrow. When its mines are explored they are found to consist 

 of irregularly radiating and connected tunnels, rarely going to a 

 greater depth than six or eight inches, or extending outward over a 

 horizontal area of more than twelve or fifteen inches. Here and 

 there in their course and at their extremities and at various depths 

 are chamber-like enlargements in which their eggs and young and 



