47 6 .l\TS. 



them from the rear. The_\ neither hesitated nor stopped till they 

 reached a large siil>scricca nest about 25 m. from their own, on the top 

 of the embankment. This nest was under and around a couple of 

 large, flat stones, and had two entrances a short distance apart. There 

 \vere a few snbsericea sauntering about the entrance, but as soon as 

 they scented the approaching army they scampered into their nest. 

 The amax.ons arrived at 2.40 P. M. and at once poured into the two 

 entrances in a mass like wine being poured into a couple of funnels. 

 Two minutes later the first brcviceps emerged with a cocoon in her jaws 

 and was at once followed by a file of others similarly laden. They 

 started for home in great precipitation. One that was timed made the 

 entire distance of 25 m. in a little more than four minutes. As the 

 army must have comprised fully 1,000 workers, there was soon a long 

 file, each carrying a larva, nude pupa or cocoon. I returned to the 

 subsericea nest in time to see a few workers of this species rush out 

 of the opening with larvae, run the gauntlet of the amazons and make 

 off to the open ground beyond. From time to time a breviceps would 

 emerge from the nest carrying a subsericea worker, take it a few 

 centimeters from the opening and put it down. To my surprise the 

 black ant scrambled to her feet and ran away uninjured. I saw this 

 performance repeated more than a dozen time by different amazons. 

 Not a single subsericea was killed or even maimed ! The plundering 

 of the nest continued, the breviceps returning repeatedly from their 

 own nest to get more pupge. By 2.55 the number of these brought out 

 of the nest had dwindled considerably and at 3.06 the supply ceased 

 altogether. Nevertheless the brcviceps kept entering the nest and 

 coming out with empty jaws till 3.15 when they began to straggle home. 

 The last ones left the pillaged formicary at 3.30 and moved away 

 slowly or sauntered about as if reluctant to return home without booty. 

 The feverish excitement so apparent in these insects a few moments 

 before had suddenly subsided. At the entrance of their own formicary 

 the slaves were running about in considerable numbers and seemed to 

 be greatly excited over the quantities of booty that were being brought 

 in. Soon, however, both slaves and breviceps entered their nest and 

 all was quiet. I again went back and found the subsericea cautiously 

 returning to their pillaged nest. On raising the stones I found a great 

 many unharmed workers in the galleries but not a single larva or pupa. 

 These ants must have remained in their nest during the whole time 

 that the rape of their brood was in progress ! The foray was remark- 

 able on account of the behavior of both species, for the subsericea. 

 though abundant, had made no attempt to protect the young which they 

 had for weeks been rearing with infinite solicitude, and the breviceps 



