1832.] SWARM OF ANTS. 35 



and others returning, burdened with pieces of green leaf, often 

 larger than their own bodies. 



A small dark-coloured ant sometimes migrates in countless 

 numbers. One day, at Bahia, my attention was drawn by ob- 

 serving many spiders, cockroaches, and other insects, and some 

 lizards, rushing in the greatest agitation across a bare piece of 

 ground. A little way behind, every stalk and leaf was blackened 

 by a small ant. The swarm having crossed the bare space, 

 divided itself, and descended an old wall. By this means many 

 insects were fairly enclosed ; and the efforts which the poor little 

 creatures made to extricate tliemselves from such a death were 

 wonderful. When the ants came to the road they changed their 

 course, and in narrow files reascended the wall. Having placed 

 a small stone so as to intercept one of tlie lines, the whole body 

 attacked it, and then immediately retired. Shortly afterwards 

 another body came to the charge, and again having failed to 

 make any impression, this line of march was entirely given up. 

 By going an inch round, the file might have avoided the stone, 

 and this doubtless would have happened, if it had been originally 

 there : but having been attacked, the lion-hearted little warriors 

 scorned the idea of yielding. 



Certain wasp-like insects, which construct in the corners of the 

 verandahs clay cells for their larvae, are very numerous in the 

 neighbourhood of Rio. These cells they stuff full of half-dead 

 spiders and caterpillars, which they seem wonderfully to know 

 how to sting to that degree as to leave them paralysed but alive, 

 until their eggs are hatched ; and the larvae feed on the horrid 

 mass of powerless, half-killed victims — a sight which has been 

 described by an enthusiastic naturalist * as curious and pleasing ! 

 I was much interested one day by watching a deadly contest 

 between a Pepsis and a large spider of the genus Lycosa. The 

 wasp made a sudden dash at its prey, and then flew away : the 

 spider was evidently wounded, for, trying to escape, it rolled down 

 a little slope, but had still strength sufficient to crawl into a 

 thick tuft of grass. The wasp soon returned, and seemed sur- 



* In a MS. in the British Museum by Mr. Abbott, •w^ho made his observ- 

 ations in Georgia; see Mr. A. White's paper in the ' Annals of Nat. Hist.,' 

 vol. vii. p. 472. Lieut. Hutton has described a sphex with similar habits in 

 India, in the ' Journal of the Asiatic Society,' toI. i., p. 555. 



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