36 
RIO DE JANEIRO 
CHAP. 
forest, is astonished at the labours of the ants: well-beaten 
paths branch off in every direction, on which an army of never- 
failing foragers may be seen, some going forth, 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 black¬ 
ened 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 themselves 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 the 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 1 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 
1 In a MS. in the British Museum by Mr. Abbott, who made his observations 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 , vol. i. p. 555. 
