296 WHEELER. 



time, but on this occasion, during the short time that I had before 

 dark overtook me, I succeeded in capturing fifty-five specimens, by 

 sweeping closely with the net over the front ranks of the ants." Al- 

 though I saw these flies on several occasions, accompanying the ad- 

 vancing armies of burchelU and darting at the ants or even at vacant 

 parts of the ground, I could see nothing that convinced me that they 

 were ovipositing. On one occasion I came upon a swarm of both sexes 

 of Stylogaster hovering over a spot where there were no Ecitons, 

 although a few workers of Giganiiops dcsirudor and Ectatomma ruidum 

 were running about in the vicinity. This observation and the fact 

 that some species of Stylogaster occur in North America north of the 

 range of Eciton, make it seem doubtful whether these flies are as 

 intimately attached to the ants as some authors have supposed. 

 They are, perhaps, attracted by the rank odor of the Ecitons. 



On several occasions I followed prey-laden files of burchclli workers 

 to their temporary nests under great logs, but was so severely stung 

 and bitten when I attempted to make closer observations that I had 

 to desist. On the morning of July 19 my son Ralph discovered a 

 colony in a more favorable situation for study only a few hundred 

 yards from the laboratory. The ants had selected a dead tree trunk 

 about a yard in diameter, hollow but still standing. At its base there 

 was a long narrow hole, nearly two feet high covered, except for a small 

 opening near the ground, with a huge, inert mass of workers, dark 

 brown and punctuated here and there with the ivory-white heads of 

 the soldiers. Into the small opening below the cluster a dense file of 

 workers was pouring, laden with prey of all kinds, including many 

 larvse of alien ants. After Mr. Tee Van had photographed the pendent 

 cluster, I stirred it up with a stick, in the hope of finding the queen, but 

 was attacked so viciously that I had to leave the premises. Return- 

 ing the following day I found that the ants had all withdrawn into the 

 roomy cavity of the tree trunk, leaving the long opening fully exposed 

 to view. Through it the colony could be dimly seen in great masses 

 draped on the walls of the cavity. Early in the morning of July 21st 

 Mr. Alfred Emerson and I decided to smoke the ants out and, if 

 possible, to secure their queen. We ringed the legs of two chairs 

 with carbolated vaseline, planted them in front of the opening, 

 crouched on their seats and with long tweezers placed in the bottom 

 of the cavity a lot of moist bamboo leaves and paper. A match was 

 applied and soon a dense smudge filled the cavity and even issued 

 from cracks in the old wood at a height of nearly twenty feet from the 

 ground. The ants remained quiet for some time, but when the smoke 



