XIV ORB-WEBS 347 
to which the spider can put in the viscid spiral, which it com- 
mences at the cirewmference. 
Its action now becomes exceedingly careful and deliberate, 
though by no means slow, and so great is its absorption in the 
work that it may be observed quite closely with a hand-lens 
without fear of interrupting it. The proceeding consists in 
drawing out from its spinnerets with one (or both) of its hind 
legs successive lengths of a highly elastic line, which it stretches 
just at the moment of fixing it to a radius, and then lets go 
with a snap. There is no hesitation or pause for consideration, 
but there is a peculiar deliberateness in drawing out each length 
of the thread which, together with stretching and sudden re- 
lease, require explanation. Now, it has already been mentioned 
that the framework and radii of the snare are not at all moist or 
adhesive. This, however, is not the case with the spiral, upon 
which the spider chiefly relies in capturing its prey. <A close 
examination of it—even with the naked eye—will show it to 
be beaded over with little viscid globules which, under a low 
magnifying power, are seen to be arranged with remarkable 
recularity. 
A very convenient method of investigation is to carry off a 
newly-constructed web—or, better still, one not quite finished— 
on a piece of plate glass, to which it will adhere by reason of 
the viscid spiral, and on which it may be examined at. leisure. 
Fia. 190.—-A, B, C, D, Stages in the formation of the viscid globules of the web. 
Immersion in a staining fluid will colour the viscid spiral, and 
show its structure in a striking manner. It will appear to con- 
sist of a thread strung with beads of two sizes, occurring with 
pretty uniform alternation, though two of the larger beads are 
often separated by two or more of the smaller. 
Until recently it was supposed that the deposition of these 
beads upon the spiral line was a subsequent operation, and, in view 
