Nets of Geometric Spiders 183 
now to be spun from the circumference around the centre, which may be 
regarded as constituting the most important part of the snare. It con- 
sists of a fine thread closely studded with minute dew-like globules, easily 
separable from each other by extending the elastic filament on which 
they are arranged. They are, in fact, globules of viscid gum, as is proved 
by their adhering to the finger and retaining dust thrown upon the net, 
while the unadhesive radii and exterior threads remain unsoiled. These 
viscid threads alone retain the insects which fly into the net, and as they 
lose their adhesive property by the action of the air, it is requisite that 
they should be frequently renewed, a process not neglected by the Spi- 
der, which evinces a perfect consciousness of its necessity. Placing her- 
self at the circumference of the net, and fastening her viscid thread to the 
end of one of the radii, the Spider walks up that radius towards the cen- 
tre, till she comes in contact with the last produced circumyolution of the 
unadhesive spiral line, along which she passes to the adjoining radius, 
drawing out the thread in her transit with the claws of the hind leg 
nearest to the circumference. She then transfers the thread to the claws 
of the other hind leg, and passing down the radius at which she has just 
arrived towards the circumference, she places the foot of the hind leg 
previously employed in drawing out the thread, on that point in the ra- 
dius to which her filament is to be attached, and bringing the spinners to 
the spot there makes it secure. The precise place in each radius at 
which to fix the thread, is always ascertained by the situation of the foot 
of the hind leg, and this is determined by touching with the feet of those 
legs nearest the circumference, the marginal line, or, when the structure 
of the net is further advanced, the last-formed circumyolution of the viscid 
spiral line. As this last line approaches the several circumvolutions of 
the unadhesive spiral line, the Spider bites them away, being sensible 
that they are no longer of any use to her, and this fact explains why they 
are never seen intermixed with the circumyolutions of the former in 
finished nets. The viscid spiral line, whose circumyolutions are nearly 
equidistant, being separated by a space of one or two lines, is thus pro- 
duced till it extends to the most proximate circumvolutions of the unadhe- 
sive spiral line, which occupying the central part of the net are suffered 
to remain ; it is then discontinued, and the Spider making choice of some 
retired spot in the vicinity, there constructs a cell in which she may con- 
