1672 



ZOOLOGICAL SOCIETY BULLETIN 



tra-specialization of fighting paraphernalia, 



still active when opportunity gave it play. At 

 the first hint, by sound or smell, of danger, the 

 big soldier whirled outward and. rearing high 

 on his legs, brandished his mighty blades in 

 mid-air. Here was an ideal pacifist, who could 

 turn his sword into a ploughshare at will, and 

 vet keep the former unsheathed for instant use. 



When I watched more closely, I detected 

 more delicate gradations of mutual aid. At the 

 same level in two columns of ascent, the same 

 stratum of hard sand was encountered. To one 

 column the sand presented a rough surface 

 which gave a good foothold. Here the single 

 line of ants which was ranged along the lower 

 edge of the trail, in lieu of hand-rail, all faced 

 downward, so that the ants passing above them 

 walked partly on the abdomens and partly on 

 the hind-legs of their fellows. In the second 

 column, the surface of the sand was smooth, 

 and here the burdened ants found great difficul- 

 ty in obtaining a foothold. In this instance the 

 supporting gang of ants faced upward, keeping 

 their place solely by their six, sturdy legs. This 

 left head and jaws free, and in almost every 

 case they helped the passage of the booty by a 

 system of passing from jaw to jaw. like a line 

 of people handing buckets at a fire. The right- 

 ful carriers gave up their load temporarily and 

 devoted their attention to their own precarious 

 footing. 



I learned as much from the failures of this 

 particular formation as from its successes. 

 Once a great segment of wood-roach was too 

 much for the gallant line clinging to the sides 

 of the pit. and the whole load broke loose and 

 rolled to the bottom. Of the hand-rail squad 

 only two ants remained. Yet in four minutes 

 another line was formed of fresh ants — ants 

 who had never been to the spot before — and 

 again traffic was uninterrupted. I saw one ant 

 deliberately drop his burden, letting it bounce 

 and roll far down to the bottom of the pit, and 

 instantly take his place in the line of living 

 guard-rails. The former constituents of the line 

 had clung to the roach segment through all its 

 wild descent, and until it came to rest at the 

 bottom. Without a moment's pause they all at- 

 tacked it as if they thought it had come to life, 

 then seized it and began tugging it upward. In 

 a fraction of time, without signal or suggestion 

 or order, the handrails had become porters. The 

 huge piece of provender had rolled close to an 

 ascending column on the opposite side of the 

 pit, and up this new trail the bearers started, 

 pulling and pushing in unison, as if they had 



been droghers and nothing else throughout the 

 whole of their ant-existence. 



One climax of mutual assistance occurred 

 near the rim of the pit on a level with my eyes. 

 where one column passed over a surface which 

 had been undermined by heavy rain, and which 

 actually overhung. I watched the overcoming 

 of this obstacle. All the ants which attempted 

 to make their way up at this point lost their 

 footing and rolled headlong to the bottom. By 

 superformicine exertions a single small worker 

 at last won a path to the rim at the top. Around 

 the edge of the pit innumerable ants were con- 

 stantly running, trying, on their part, to find 

 a way down. The single ant communicated at 

 once with all which came past, and without hes- 

 itation a mass of the insects formed at this spot 

 and began to work downward. This could be 

 done only by clinging one to the other; but more 

 and more clambered down this living ladder, 

 until it swayed three inches in length, far out 

 over the vastness of the pit. I had never lost 

 sight of the small worker, who had turned on 

 his tracks and was now near the bottom of the, 

 ladder, reaching wildly out for some support — 

 ant, grass or sand. I was astonished to see 

 that, as the length and consequent weight of 

 the dangling chain increased, the base support 

 was correspondingly strengthened. Ant after 

 ant settled itself firmly on the sand at the top, 

 until a mat of insects had been formed, spread 

 out like animate guy ropes. 



At last the ultimate ant in the rope touched 

 the upraised jaws of a soldier far below. The 

 contact acted like an electric shock. The far- 

 thest ant in the guy-rope gang quivered with 

 emotion, a crowd of ants climbed down and an- 

 other up, atid bits of insect and spider prey 

 began to appear from the depths of the pit. over 

 the living carpet suspended from the brim. Eor 

 an inch the droghers climbed over the bodies 

 braced against the cliff. Then, where the sur- 

 face became smooth, the dangling chain came 

 into use. Before the rim of the pit was reached, 

 the chain had become a veritable hollow tube 

 of ants, all with heads inward, and through this 

 organic shaft passed the host from the ascend- 

 ing column. But it was far more than any 

 mechanically built tube. When an extra large 

 piece of loot came up. the tube voluntarily en- 

 larged, the swelling passing along until the 

 booty and its bearers emerged at the top. 



Within five minutes after this last column 

 was completed, there passed over it, out of the 

 pit. a daddy-long-legs with legs trailing, per- 

 haps the same one which I had seen in the 



