ON ARACHN1DA. 
467 
occupy the angles. Their surface forms a triangular plane, 
but which becomes a little concave in consequence of the 
natural sinking in of the web. Its threads are very close, cross 
each other, and being strongly bound together by their 
viscosity, give it some resemblance to a very fine stuff 1 , but 
which can, nevertheless, retain the various insects which 
come there, on which these animals feed, and frequently even 
coleoptera of tolerable size. Many loose, and as it were, 
floating threads, compared by Lister to cordages, or sail-yards 
of vessels, are placed on the upper side of the web, and 
become sorts of snares for the insects which get embarrassed 
there. Immediately at the angle formed by the union of the 
two walls, the spider weaves a cylindrical tube, having one of 
its apertures above, the other underneath. Tt there remains 
constantly in ambush, the head being turned forwards ; as 
soon as a fly, or any other little animal is arrested in the web, 
it runs forward, promptly seizes its prey, and drags it to the 
bottom of its lodge, for the purpose of sucking it with the 
greater facility. If any pressing danger should frighten the 
spider, it takes to flight, and speedily escapes through the 
low- er aperture of its habitation. Homberg has also described, 
in the memoirs of the Academy of Sciences, 1707, the man 
ner in which these animals manage in spreading their webs. 
The cavities which are found under stones, in rubbish, also 
serve them for the purpose of retreat. Lister has occasionally 
encountered them in the w 7 oods. He has seen the male and 
female on the same w T eb, in the commencement of June, the 
season of their amours. Having thrown some flies to them, 
each individual took one. The laying takes place towards 
the end of the following month. The cocoon has a double 
envelope of very w hite silk. It is placed near the anterior 
aperture of the tube where the spider remains, and it seems to 
form a portion of the web. The eggs are whitish, and have 
no adherence. Audebert brought up, and kept for some 
H h 2 
