THE VOYAGE OF THE BEAGLE 



47 



with very long fore-legs, and which appears to belong to an 

 undescribed genus, lives as a parasite on almost every one 

 of these webs. I suppose it is too insignificant to be noticed 

 by the great Epeira, and is therefore allowed to prey on the 

 minute insects, which, adhering to the lines, would other- 

 wise be wasted. When frightened, this little spider either 

 feigns death by extending its front legs, or suddenly drops 

 from the web. A large Epeira of the same division with 

 Epeira tuberculata and conica is extremely common, espe- 

 cially in dry situations. Its web, which is generally placed 

 among the great leaves of the common agave, is sometimes 

 strengthened near the centre by a pair or even four zigzag 

 ribbons, which connect two adjoining rays. When any large 

 insect, as a grasshopper or wasp, is caught, the spider, by 

 a dexterous movement, makes it revolve 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 silk- 

 worm. The spider now examines the powerless 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 eaught in the irregular web 



