ON THE NETS OF GEOMETRIC SPIDERS. 279 
her progression, she forms about twenty or thirty 
radii, composed of double lines, diverging from the 
centre to the circumference, and giving the net the 
appearance of a wheel. She then proceeds to the 
centre, turns herself round, and pulls each radius 
with her feet, to ascertain its strength, breaking 
such as seem defective, and replacing them by 
others. Her next proceeding is to produce, round 
the centre of the net, a spiral line extending thence 
to the circumference, and intersecting the radii, to 
which she attaches it by pressing her spinners 
against them. This spiral line, a few of the more 
central circumvolutions of which*are much nearer 
to each other than are those removed to a greater 
distance from that point, serves as a temporary 
scaffolding for the spider to walk over, and also to 
keep the radii properly stretched during her suc- 
ceeding operations. It, together with the radii and 
marginal lines, is composed of unadhesive silk; but 
a spiral line has now to be spun, from the circum- 
ference around the centre, which may be regarded 
as constituting the most important part of the snare. 
It consists of a fine thread, closely studded with 
minute dew-like globules, easily removable to a 
greater distance 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 
