78 Bulletin American Museum of Natural History. [Vol. XXII, 



Experiment 35. July 9, 10 a.m. Placed a rubicunda female in a nest con- 

 taining only 4 subsericea workers and about 200 worker and two female cocoons. 

 The workers^at once grabbed cocoons and fled into the light chamber. The 

 female ran about the dark chamber and escaped into the light chamber, but at 

 once returned, forcing her way through the entrance, which was much obstructed 

 with earth, and began to collect and pile up the cocoons in a corner. The workers 

 kept returning and stealthily snatching cocoons from the edge of her pile and 

 hurrying away with them into the light chamber. She perceived one of these 

 returning workers, pounced on her and killed her with a blow of her mandibles. 

 This first murder thoroughly aroused her and she began to prance to and fro. 

 Another worker returned, but before she could be grabbed had seized one of 

 the female's antennae. The two ants now began to pull in opposite directions, 

 while the remaining workers made haste to carry the cocoons into the light 

 chamber. At 11.30 the female had killed the worker and freed herself without 

 losing her funiculus and was in the act of killing a third worker. She at once 

 began to bring the cocoons back to the comer in the dark chamber. She re- 

 moved 80 of them in 30 minutes, that is at an average rate of 2| per minute. 

 Only four cocoons were overlooked and left in the light chamber. Then she 

 returned to the dark comer and began to stack up the cocoons. Meanwhile 

 the single surviving worker ran about in great trepidation, fleeing whenever 

 the female approached her, and endeavoring to escape from the nest without 

 making any attempt to carry away the cocoons. Whenever the dark chamber 

 was uncovered the female at once tried to secrete her cocoons in some other 

 part of the nest, thus showing a clear sense of proprietorship. By 2 p. m. she 

 had also secured three of the four cocoons remaining in the light chamber. 

 July 10 to^ii. The female had built all the cocoons into a more compact pile 

 andjvas resting on them__with half -open jaws ready to attack any comer. July 

 12. During the night a callow worker and callow female subsericea hatched. 

 Two more callow workers and several naked pupae from a wild colony were 

 placed in the light chamber. These were found by the female and carefully 

 removed to her pile. She paid^ no^ attention to the s^ibsericea female. The 

 callows joined the female rubicunda in caring for [the pupae.|^ At 5 p. m. one of 

 the older callows was seen in the act of freeing a young callow from its cocoon. 

 July 14 another callow hatched. The female rubicunda was very solicitous about 

 the cocoons whenever the dark chamber was uncovered. There were now one 

 female and five worker subsericea. This female also at times helped in stacking 

 up the cocoons. July 15, 7 a. m. There were 8 workers and one callow in 

 the act of hatching and by evening others had been divested of their pupal 

 envelopes. July 16, [7 a.m. there were 25 workers. At 2.30 the rubicvinda 

 female was surprised in the act of licking a callow and carrying it a short dis- 

 tance as if to hide it. By 4.30 p. m. there were 34 callows. At 7 p. m. the female 

 was seen to open a cocoon. She held it firmly in her two fore feet while she 

 made a rent in the center of its ventral surface with her mandibles. July 17, 

 7.30 A. M. there were 45 workers altogether, most of them still very callow. The 

 female rubicunda spent most of her time opening cocoons and freeing the cal- 

 lows from their pupal envelopes. By 5 p.m. there were 55 workers and by the 

 following morning (July 18, 7.30 a.m.) 63 were covanted. The number rose to 

 80 by 7.30 A.M. July 19. The female still tried to hide her cocoons when- 

 ever the nest was uncovered. Many of the workers were bus}' assisting the 



