THE DRU'ER AXD LEGIONARY ANTS. 259 



dissected bodies of insects. I was surprised to see in this living nest 

 tubular passages leading down to the center of the mass, kept open 

 just as if it had been formed of inorganic material Down these holes 

 the ants who were bringing in booty passed with their prey. I thrust 

 a long stick down to the center of the cluster and brought out clinging 

 to it many ants holding larvae and pupae which were probably kept 

 warm by the crowding together of the ants. Besides the common dark- 

 colored workers and light-colored officers, I saw there many still larger 

 individuals with enormous jaws. These they go about holding wide 

 open in a threatening manner, and I found, contrary to my expectation, 

 that they could give a severe bite with them, and that it was difficult 

 to withdraw the jaws from the skin." These observations recall 

 the clustering habit of the African Anonuna as described by Savage, 

 a habit which seems to be common to a number of Ecitons. I have 

 seen it in E. sumichrasti, schinitti and opacithorax. 



Excellent observations on the Mexican species were made by Sumi- 

 chrast (1868) from whom I quote the following: "The most charac- 

 teristic trait of the ants of this genus consists in the inroads or 

 migrations which they undertake at undetermined epochs, but in rela- 

 tion, it appears to me, with the atmospheric changes. What traveller, 

 passing over the ticrra calicnte, has not encountered the phalanxes of 

 tcpeguas upon the path of the primitive forests? What inhabitant of 

 these countries has not, at least once, been unpleasantly torn from the 

 arms of sleep by the invasion of his domicile by a black army of 

 soldados ? 



' The purpose of these expeditions of Eciton is, without doubt, 

 multiple, for the circumstances that these sorties, as one may call them, 

 coincide more often with a change of season, hardly permits one to 

 consider them exclusively as simple razzias undertaken at the expense 

 of other insects. One can believe them to be sometimes expeditions 

 of pillage, sometimes changes of domicile, veritable migrations. I 

 believe that the following facts, which passed under my observation 

 at the hacienda of Potrero, near Cordova, at the end of September of 

 the past year, show proof of this. During about three months, a 

 colony of soldados [E. predator] had been domiciled under a little 

 bridge formed by some rough trunks of trees bound together by a heap 

 of vegetable mould. The continued excavation which engaged the ants 

 on the under side of the bridge, threatened to cause the disappearance 

 of all the earth which covered the flooring. Every day I watched these 

 labors in the hope of discovering at last the interior of the formicary, 

 but this hope was disappointed, for on the thirtieth of September, in 

 the morning, I found the nest completely abandoned. Its inhabitants 



