ADOPTION OF QUEEN BY ALIEN SPECIES. 299 



minutes the americanus queens were huddled together near a 

 moist sponge I had provided for them but the latipes queens, 

 always more restless in confinement, were still running about 

 in the nest. They were continually running over or through the 

 bunch of americanus queens and sometimes remained with them 

 for several minutes, yet I never saw the slightest signs of hos- 

 tility either on the part of the americanus or the latipes queens. 

 The next morning 3 of the latipes queens were dead and two days 

 later the other 2 died, yet I feel quite sure that death was not 

 caused by any hostility on the part of the americanus queens. 

 In the same length of time 7 americanus queens died, but there 

 have been no more deaths up to the present time. I feel sure 

 that a number of the deaths of the americanus queens were due 

 to injuries received when I picked them up off the ground. The 

 fact that the nuptial flight of latipes and americanus may occur 

 at the same time and that the queens of the two species are not 

 hostile to one another suggests the possibility of a colony being 

 founded in common by queens of the two species. This possi- 

 bility should be tested by experiment. However, I think tem- 

 porary parasitism a more plausible explanation of the mixed 

 colonies mentioned above because of the fact that the latipes 

 queen is of a more nervous temperment, and even though there 

 were no hostilities between the two queens she would not be 

 satisfied to settle down in a little cell with the phlegmatic ameri- 

 canus queen and wait nine or ten months for the appearance 

 of workers. This nervous disposition, however, is exactly suited 

 to running about over the ground until the queen happens to 

 run into a small Lasius colony, and when she gets on to the brood 

 she is perfectly satisfied to settle down as is shown by the ex- 

 periments. 



The adoption of the latipes queen by the colony of L. inter- 

 jectus may be looked upon as adding weight to one of the ex- 

 planations quoted above for the occurrence of the two forms of 

 females, namely, that the alpha form may be a hybrid between 

 the beta female and a male claviger. Since adoption occurred 

 with interjectus it might also be expected to occur with the nearly 

 related claviger if enough cases were tried. Again the females of 

 claviger and interjectus are very similar so that the alpha form 



