190 j.\"/.y. 



burrow so as to form a diminutive mound, which when completed was 

 about two inches in diameter. On May 23, during the hot morning 

 hours the lYmalcs could be seen at work everywhere in the draws 

 and river bottom, often within a few inches of one another. Many 

 had already completed their burrows, which extended down obliquely, 

 to a depth of three to four inches, and had closed the opening behind 

 them. It was an easy matter to dig a dealated female from each spot 

 indicated by a small fan-shaped mound or to tempt her to the surface 

 by inserting a straw into her burrow. A wind- or rain-storm would 

 have obliterated at once all traces of the whereabouts of these insects. 

 That they actually sought the pure sand, which is also the substance 

 in which the adult colonies are found,- was seen on the top of the 

 escarpment. There each tiny draw was literally filled with incipient 

 nests, although none could be found on the hard intervening spaces 

 often hundreds of feet wide. The ants would, in fact, be quite unable 

 to excavate the hard soil. The comparatively small number of adult 

 colonies in the vicinity proved that but few of these isolated females 

 ever succeed in rearing a colony. They are doomed to rigid, all but 

 catastrophic, elimination, which only the best endowed and most favor- 

 ably situated can survive. 



In the foregoing paragraphs attention has been repeatedly called 

 to the fact that an ant colony is started by a single isolated female. 

 This requires some qualification, since under very exceptional circum- 

 stances a couple of females from the same maternal nest may meet 

 after their marriage flight and together start a colony. During August, 

 1904, I found two dealated females of Lasiits brcvicornis occupying 

 a small cavity under a clump of moss on a large boulder near Cole- 

 brook, Conn. They had a few larvae and small cocoons and a couple of 

 small callow workers. The colony was transferred to an artificial nest 

 and kept for several days. Both females were seen to take part in 

 feeding and caring for the single packet of larvae and freeing the re- 

 maining callows from their cocoons. Without doubt these twin females 

 were sisters that had accidentally met under the same bit of moss and 

 had renewed the friendly relations in which they had lived before 

 taking their nuptial flight. June 16, 1907, I found a very similar colony 

 consisting of two dealated queens of L. flai'its near Sion in the valley 

 of the Rhone. They were in a small earthen cavity under a stone and 

 had eggs and young larvae, which they hastened to conceal when the 

 nest was uncovered. These cases are of considerable interest because, 

 as a rule, sister ants seem to be averse to such postnuptial partnerships. 



Among certain ants the females may be retained and dealated by 

 the workers in the parental nest, or carried in and readopted just after 



