602 PROCEEDINGS OF THE ACADEMY OF [Sept., 



Formica was somewhat larger than either of the Stenamma queens, 

 and was very active. She remained in association, at times, with 

 these queens until November 28, a period of two months, and was 

 then finally removed from their nest. Five and a half months 

 later. May 11, 1902, I put the 'four queens into a clean Petri cell, 

 and introduced to their cell a Formica fusca subsericea from Cen- 

 tral Park, New York City. The introduced Formica exhibited 

 great fear in the presence of the Stenamma queens, and made 

 energetic efforts to escape from the cell ; but the queens showed 

 neither fear nor dislike of the Formica, and never opened their 

 mandibles when I forced the Formica to touch them. The fears of 

 the Formica gradually subsided, and after two weeks' residence 

 she would touch antenuse with the queens in most friendly fashion. 

 The Formica was thereafter often huddled with the queens, and she 

 lived with them until May 31, 1902, when the four queens were 

 killed by an accident. The Formica survived and I put her into a 

 similar cell with C colony queens that had never fostered a For- 

 mica. These queens separately and together attacked the Formica 

 and killed her after two days' persecution. It is possible that the 

 odor of the Formica remained in the nest inhabited by the four 

 Stenamma queens, and that they had not to exercise memory in 

 the case. But the odor of the Wood's Hole Formica and that of 

 the Central Park Formica was not identical, for I put Formica 

 fusca subsericea of these two places together and fovmd that they 

 fought each other to the death. 



Exjieriment b. — On the 22d of August, 1901, I sequestei-ed 

 pupse and larvie from the natural nest of the C colony, and then 

 segregated ants hatched therefrom between September 4 and Sep- 

 tember 10. These segregated ants had no association Avith any 

 other ant. On the 26th of September a large Formica fusca sub- 

 sericea hatched out from a pupa that I had put into their cell Ihree 

 days earlier, and it was kindly cared for by the little Stenammas, 

 although it was four or five times their size. On the 6th of Octo- 

 ber, the Stenammas being about one month old and the Formica 

 ten days old, I separated them, putting the Stenammas into one 

 clean Petri cell and the Formica into another. The inhabited cells 

 were respectively cleaned once a week,* and were cleaned seven 



* The cells were cleaned, after temporarily removing the ants to 

 another clean cell, by washing the cell and its enclosed sponge Avith 



