FORMICARY . 189 



have regular divisions of laborers, numbers mounting the trees 

 and cutting off the leaves in irregularly rounded pieces the size 

 of a shilling, another relay carrying them off as they fall." 

 "The heavily laden fellows, as they came trooping in, all de- 

 posited their load in a heap close to the mound. About the 

 mound itself were a vast number of workers of a smaller size. 

 The very large-headed ones were not engaged in leaf-cutting, 

 nor seen in the processions, but were only to be seen on dis- 

 turbing the nest." Bates also says, "I found, after removing 

 a little of the surface, three burrows, each about an inch in 

 diameter ; half a foot downward, all three united in one tubular 

 burrow about four inches in diameter. To the bottom of this I 

 could not reach when I probed with a stick to the depth of four 

 or five feet. This tube was perfectly smooth and covered with 

 a vast number of workers of much smaller size than those oc- 

 cupied in conveying the leaves ; they were unmixed with any 

 of a larger size. Afterwards, on probing lower into the bur- 

 row, up came, one by one, several gigantic fellows, out of all 

 proportion, larger than the largest of those outside, and which 

 I could not have supposed to belong to the same species. Be- 

 sides the greatly enlarged size of the head, etc., they have an 

 ocellus in the middle of the forehead ; this latter feature, added 

 to their startling appearance from the cavernous depths of the 

 formicarium, gave them quite a Cyclopean character." 



Of another species, the (Ec. sexdentata, Mr. Smith quotes 

 from Rev. Hamlet Clark, that at Constancia, Brazil, the pro- 

 prietor of a plantation used every means to exterminate it and 

 failed. " Sometimes in a single night it will strip an orange or 

 lemon tree of its leaves ; a ditch of water around his garden, 

 which quite keeps out all other ants, is of no use. This spe- 

 cies carries a mine under its bed without any difficulty. In- 

 deed, I have been assured again and again, by sensible men, 

 that it has undermined, in its progress through the country, the 

 great river Paraiba. At any rate, without anything like a nat- 

 ural or artificial bridge, it appears on the other side and con- 

 tinues its course." This testimony is confirmed by Mr. 

 Lincecum (Proceedings of Academy of Natural Sciences, 

 Philadelphia, 1867, p. 24) in an interesting account of the (Ec. 

 Texana, which he has observed for eighteen years. He states 



