1906.] Wheeler, Founding of Colonies by Queen Ants. 63 



lot of twigs, grass-roots, etc. Three larvae were seen at this time, one 

 nearly mature and one only about a quarter grown. On the twigs and 

 lower surface of the stone there were some twenty empty puparia 

 from which the flies had already escaped. The three larvae were 

 placed in a Fielde nest containing several hundred consocians workers. 

 The two older ones at once applied their fiat creeping -soles to the glass 

 bottom of the nest and with their hard rough backs resisted the attacks 

 of the workers. The small larva was not so successful. The ants 

 turned it over on its back and for two days kept licking and biting it 

 till it was killed and reduced to a small granule. The two large 

 larvae kept crawling slowly about the nest. They raised the anterior 

 end of the body a little distance froin the glass surface and moved the 

 small pointed head, which is just beneath it, from side to side appar- 

 ently in search of food. They showed signs of uneasiness when ex- 

 posed to strong light. They remained in good condition till Aug. 23, 

 when one of them disappeared. It had probably been eaten by the 

 ants. The other lived till Sept. 10. Some days previously it had begun 

 to shrivel, and finally dried up without losing its hold on the glass. I 

 have failed to ascertain the nature of the food of these larvae. 

 July 25 I again visited the wild consocians nest but found that the 

 ants had moved away. On the twigs there were two more half -grown 

 but rather emaciated Microdon larvae which had been left behind by 

 the ants. These together with a couple of old puparia are shown in 

 PI. X, Fig. 2. The fact that these larvae were so emaciated, and 

 died soon after they were placed in the same Fielde nest with the 

 others, shows that the presence of the ants is in some way essential 

 to the well-being of these singular synoeketes. 



2. Formica difficilis Emery. 



The typical F. difficilis like its variety consocians , is a rare and local 

 ant. Judging from my experience during the past summer it is even 

 rarer then its variety, since I have hitherto been able to find only two 

 colonies, one near Mt. Vernon, N. Y., the other at Bronxville, N. Y. 

 Each of these was nesting under an isolated stone. The ants of the 

 Bronxville colony, which was found Aug. 12, had heaped up a quantity 

 of dead leaves, bits of grass, etc., and were guarding, partly in this pile 

 of debris and partly under the stone, a great number of worker pupae. 

 Dozens of these were naked, a condition which is rare in ants of the 

 rufa group and had not been observed in the colonies of the Con- 

 necticut variety. The minim workers in this colony were very dark 

 and smaller than the smallest commonly found in the consocians col- 



