38 RIO DE JANEIRO chap. 



very rapidly, and at the same time emitting a band of threads 

 from its spinners, soon envelops its prey in a case like the 

 cocoon of a silkworm. The spider now examines the power- 

 less victim, and gives the fatal bite on the hinder part of its 

 thorax ; then retreating, patiently waits till the poison has 

 taken effect. The virulence of this poison may be judged of 

 from the fact that in half a minute I opened the mesh, and 

 found a large wasp quite lifeless. This Epeira always stands 

 with its head downwards near the centre of the web. When 

 disturbed, it acts differently according to circumstances : if there 

 is a thicket below, it suddenly falls down ; and I have distinctly 

 seen the thread from the spinners lengthened by the animal 

 while yet stationary, as preparatory to its fall. If the ground 

 is clear beneath, the Epeira seldom falls, but moves quickly 

 through a central passage from one to the other side. When 

 still further disturbed, it practises a most curious manoeuvre : 

 standing in the middle, it violently jerks the web, which is 

 attached to elastic twigs, till at last the whole acquires such a 

 rapid vibratory movement, that even the outline of the spider's 

 body becomes indistinct. 



It is well known that most of the British spiders, when a 

 large insect is caught in their webs, endeavour to cut the lines 

 and liberate their prey, to save their nets from being entirely 

 spoiled. I once, however, saw in a hot-house in Shropshire a 

 large female wasp caught in the irregular web of a quite small 

 spider ; and this spider, instead of cutting the web, most per- 

 severingly continued to entangle the body, and especially the 

 wings, of its prey. The wasp at first aimed in vain repeated 

 thrusts with its sting at its little antagonist. Pitying the wasp, 

 after allowing it to struggle for more than an hour, I killed it 

 and put it back into the web. The spider soon returned ; and 

 an hour afterwards I was much surprised to find it with its jaws 

 buried in the orifice through which the sting is protruded by 

 the living wasp. I drove the spider away two or three times, 

 but for the next twenty-four hours I always found it again 

 sucking at the same place. The spider became much distended by 

 the juices of its prey, which was many times larger than itself. 



I may here just mention that I found, near St. ¥6 Bajada, 

 many large black spiders, with ruby-coloured marks on their 

 backs, having gregarious habits. The webs were placed verti- 



