284 ON THE NETS OF GEOMETRIC SPIDERS. 
tinued to the centre of the net is obvious, for by this 
arrangement the spider is enabled to superintend her 
toils without incurring the risk of being entangled 
in them. The species referred to by Messrs. Kirby 
and Spence as always leaving a vacant interval 
round the smallest, first-spun circles which are 
nearest to the centre of her net, produces fewer of 
those small circles than almost any other Geometric 
Spider which has fallen under my notice, except the 
long slender-bodied species, TZetragnatha extensa, 
Latreille, whose economy is very similar; conse- 
quently, if the viscid line were prolonged till it 
made a near approximation to them, the unadhesive 
lines about the centre would be too closely circum- 
scribed, and the spider would be subjected to great 
inconvenience. 
Hitherto I have supposed the spider to form her 
snare in places evidently easy of access to her; but 
it is not unusual to see nets fixed to objects be- 
tween which it is quite impossible that a commu- 
nication can have been established by any process 
alluded to above—between distant plants, for ex- 
ample, growing in water. “Here then,” as the 
authors of the ‘Introduction to Entomology’ ob- 
serve, “a difficulty occurs. How does the spider 
contrive to extend her main line, which is often 
many feet in length, across inaccessible openings 
of this description?” To this curious fact my 
attention has long been directed, and I have 
