THE NATURALIST ON THE RIVER AMAZONS. 



liabits of the Eciton genus is their hunting 

 for prey in regular bodies or armies. It is 

 Iliis which chiefly distinguishes them from 

 Ihe genus of common red stinging ants, sev- 

 <-ial species of which inhabit England, whose 

 Jiabit is to search for food in the usual irregu- 

 J:ir manner. All the Ecitons hunt in large, 



< rganized bodies ; but almost every species 

 lias its own special manner of hunting. 



Eciton rapax. One of the foragers, Eciton 

 mpnx, the giant of its genus, whc.se worker- 

 majors are half an inch in length, hunts in 

 single file through the forest. There is no 

 division into classes among its workers, 

 3ilt hough the difference in size is very great, 

 s-ome being scarcely crie half the length of 



< thers. The head and jaws, however, are 

 always of the same shape, and a gradation in 

 * ze is presented from the largest to the 

 smallest, so that all are able to take part in 

 Ihe common labors of the colony. The chief 

 employment of the species seems to be plun- 

 dering the nests of a large and defenceless 

 tint of another genus (Formica), whose man- 

 gled bodies I have often seen ID th? ; r posses- 

 sion as they were marching away. The 

 a! mies of Eciton rapax are never very nu- 

 merous. 



Eciton legionis. Another species, E. le- 

 gionis, ngrees with E. rapax in having 

 v orkers not rigidly divisible into two classes ; 

 but it is much smaller in size, not differing 

 greatly in this respect fiom our common 

 English red ant 'My i mica rubra), which it 

 also resembles in color. The Ecitou legicnis 

 !ives in open places, and was seen only on 

 jhe sandy campos ot Santarcm. The move- 

 ments ofits hosis were, therefore, much more 

 rasy to observe than those cf nil other kinds, 

 ivhich inhabit solely the densest thickets ; its 

 mug and bite also were less formidable than 

 ihose of other species. The armies of E. le- 

 gionis consist of many thousands of indi- 

 riduals, and move in rather broad columns. 

 They are just as quick to break line on being 

 disturbed, and attack hurriedly and furiously 

 any intruding object, as the other Ecitous. 

 The species is not a common one;, and I sel- 

 dom had good opportunities of watching its 

 habits. The first time I saw an army was one 

 evening near sunset. The column consist- 

 ed of two trains of ants, moving in opposite 

 directions ; one train empty-handed, the other 

 laden with the mangled remains of insects, 

 chiefly larvae and pupae of other ants. I had 

 no difficulty in tracing the line to the si ot 

 from which they were conveying their 

 booty ; this was a low thicket ; the Ecitons 

 were moving rapidly about a heap of dead 

 leaves ; but as the short tropical twilight was 

 deepening rapidly, and I had no wish to be 

 iMjnighted on the lonely campos, 1 deferred 

 further examination until the next day. 



On the following morning no trace of ants 

 could be found near the place where I had 

 seen them the preceding day, nor were there 

 signs of insects of any description in the 

 thicket ; but at the distance of eighty or one 

 hundred yards, I came upon the same u 



engaged evidently on a razzia of a similar 

 kind to that of the previous evening, but 

 requiring othnr resources of their instinct, 

 owing to the nature of the ground. They 

 were eagerly occupied on 1 he face of an in- 

 clined bauk of light eartli in excavating 

 mines, whence, from a depth of eight or ten 

 inches, they were extracting the bodies of a 

 bulky species of ant of Uie genus Formica. 

 It was curious to see them crowding round 

 the orifices of the mines, some assisting their 

 comrades to lift out the bodies of the For- 

 mica3, and others tearing them in pieces, on 

 account of their weight being too great for a 

 single Eciton, a number of carriers seizing 

 each a fragment and carrying it off down the 

 slope Oa digging into the earth with a 

 small trowel near the entrance of the mines, 

 1 -found the nests of the Fonnicae, with grubs 

 and cocoons, which the Ecitms were thus 

 invading, at a depth of about eight inches 

 from the surface. The eager freebooters 

 rushed in as fast as I excavated, and seized 

 the ants in my finders as I picked them out, 

 so that I had some difficulty in rescuing a 

 few entire for specimens. In digging 1j8 

 numerous mines to get at their prey, the ia- 

 tie Ecitons seemed to be divided into parties, 

 one set excavating and another set carrying 

 away the grains of earth. When the shafts 

 became rather deep, the mining parties had 

 1o climb up the sides each time they wished 

 to cast out a pellet of earth ; but their work 

 was lightened for them by comrades, who 

 stationed themselves at the mouth of the 

 shaft, and relieve! them of their burdens, 

 carrying the particles, with an appearance 

 of foresight which quite staggered me, a 

 sufficient distance from the edge of the hole 

 to prevent them from rolling in again. All 

 the work seemed thus to be performed by 

 intelligent co-operation among the host of 

 eager little creatures ; but still there was not 

 a rigid division of labor, for some of them, 

 whose proceedings I watched, acted at one 

 time as carriers of pellets, and at another aa 

 miners, and all shortly afterward assumed 

 the office of conveyers of the spoil. 



In about two hours all the nests of For- 

 miese were rifled, though not completely, of 

 their contents, and I turned toward the army 

 of Ecitons, which were carrying away the 

 mutilated remains. For some distance there 

 were many separate limes of them moving 

 along the slope of the bank ; but a short dis- 

 tance off these all converged, and then formed 

 one close and broad column, which continued 

 for some sixty or seventy yards, and termi- 

 nated at one of those large termitariums or 

 hillocks of white ants which are constructed 

 of cemented material as hard as stone. The 

 broad and compact column of ants moved up 

 the steep sides of the hillock in a continued 

 stream ; many which had hitherto trotted 

 along empty handed, now turned to assist 

 their comrades with their heavjr loads, and 

 the whole descended into a spacious gallery 

 or mine opening on the top or the termitari- 

 um, I did not try to reach the nest which 



