640 PROCEEDINGS OF THE ACADEMY OF [Scpt., 



abdomen, with slight movements of the antennae, were the only signs 

 of life given by any of the five ants during forty-five minutes. Mean- 

 time one of the other residents came down from the roof-pane, and 

 while the yellow ant was at H with the heads of all the spellbound 

 ones turned aw^ay from her, this solicitous sister went and touched 

 three of the entranced ones, but failing to rouse them, she withdrew 

 again beyond the line of the yellow visitor's march. I was observing 

 the ants through a pane of orange-tinted glass which protected them 

 from such liglit as they were aware of/ and I several times lifted the 

 pane, letting the daylight fall full upon them, but even this stimulant 

 did not impel any of them to move. 



During all this time none of the five ants that were in the food-room 

 returned through the only ingress therefrom, the hallway H, and the 

 young, ordinarily attended upon without intermission, were wholly 

 neglected. The yellow ant finally stayed awhile in the hallway, and 

 within the ensuing five minutes all the three ants between A and B 

 began to walk slowly forward. I then shoved the other two with the 

 end of a needle, and they also moved slowly about. 



I did not again look into this nest until the following morning, when 

 I found the yellow ant dead, and carried to the rubbish pile. I then 

 introduced another ant of the same colony and of the same appearance, 

 but this second ant was no Svengali, and only the expected thereupon 

 happened. 



Yet another, introduced later, came in like manner to an immediate 

 and violent death. 



2. A wolf in sheep's clothing? 



I had in August, 1904, a nest of Crcmastogaster lineolaia, containing 

 one queen, a hundred workers, and much young in the egg, larval and 

 pupal stages. These ants had been in my care during all their lifetimes, 

 and I know that they had never met Lasins latipes in active life. In 

 the previous June I had introduced into their nest a half-teaspoonful 

 of the larvae of Lasius latipes, for them to use as food, and this alien 

 larvae had been taken care of, had become pupae, and had gradually 

 disappeared. On August 21 there hatched from what was perhaps the 

 last of these alien pupae a tiny Lasius, that the Cremastogasters per- 

 mitted to live. Its bright amber-yellow body was very conspicuous 

 among its jet-black associates. During several days the infant Lasius, 

 of a different subfamily from its foster-sisters, shared their labors and 

 passed unnoticed among them, and then it was nipped to death. 



It is probable that this Lasius, having been long among the Cremas- 

 togasters, had acquired an overlaying of their inlierent odor, concealing 

 its own, and that it thereby escaped hostile attack until such time as it 



