^4 Bulletin American Museum of Natural History. [Vol. XXII, 



life. The reactions displayed in the foregoing experiments are, more- 

 over, so definite, uniform and purposeful even in artificial nests that 

 one can hardly doubt that they are similarly manifested in a state of 

 nature. It is evident that, especially in timid incipient wild colonies 

 of F. subsericea, the females may meet with less opposition and 

 therefore with greater and more immediate success. Still the fact 

 that ruhicunda is a local ant and by no means one of our most abundant 

 species shows that the successful establishment of colonies in a state 

 of nature must be attended with considerable difficulties. The search 

 of the rubicunda female for weak or incipient subsericea colonies, even 

 in regions where the latter ant is very abundant, must often be vain or 

 illusory. This is tantamount to saying that the element of chance 

 must enter very largely into the life of the rubicunda queen, just as it 

 does into the lives of most parasitic animals. 



7. Formica sanguinea rubicunda var. subintegra Emery. 



The females of this form are much smaller than those of rubicunda 

 proper. A few of them were taken July 10 from a flourishing colony 

 containing many subsericea slaves, and were used for experiments 

 like those performed with rubictinda. They gave negative results, 

 however, for in every case the female was killed by the workers before 

 she could show an interest in the cocoons or try to collect them. It is, 

 of course, quite possible that these small females may be less pug- 

 nacious than those of the pure rubicunda and rely on amicable adoption 

 by the workers of incipient subsericea colonies rather than on killing 

 the workers and appropriating the young. The following may serve 

 as an example of the experiments performed with subintegra. 



Experiment 42. July 17. At 11.45 'P-'^- ^^ artificially dealated female 

 subintegra was placed in a nest with 7 subsericea workers and 10 pupse (5 nude 

 and 5 in cocoons) . One of the workers at once seized her by an antenna, but 

 the others at first sought to avoid her. She grabbed the irate worker by a leg 

 and tried to amputate it. While the two ants were in this predicament, a worker 

 came up and began to lick the female's head and mandibles effusively. Then 

 another worker came up and did the same, but soon departed. The female 

 tried to cut off the gaster of the worker pulling at her antenna. Meanwhile 

 another worker approached and licked the female's head. At 1.05 p.m. she 

 killed the worker that was holding her, and succeeded in extricating her an- 

 tennal funicle. She was very alert and examined all parts of the nest very 

 carefully. The workers, annoyed and frightened by the female, tried to con- 

 ceal their brood in the manger. While running about the nest the female felt 

 into the manger and was at once attacked by 3 workers simultaneously. She 

 managed to shake off two of them and to catch the third by the hind leg. She 

 dragged this worker about, stopping from time to time to curl her body as if 



