80 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
manner covered; and so moved around the web until all the corners (at 
x) were filled in, leaving the open cireular space occupied by eight scaffold 
spirals. 
The lines thus covering the angles are not strictly “spirals” although 
they belong to the spiral space, and have precisely the characteristics of 
the true spirals from which often they cannot be separated by the eye, 
without close attention. They are put in by “loops;” that is, the spider 
passes back and forth over the ends of the radii, as at x, ix, carrying her 
thread, and looping it at the extremities of corner spaces. These lines 
have therefore been designated corner loops. In point of fact the concen- 
tric lines are complete circles only when the framework of the snare 
allows an unobstructed movement entirely around the centre. This exam- 
ple is not the invariable rule of procedure, for spiders vary their modes. 
Some start at once upon the spiral concentrics and make loops (particu- 
larly at the lower part of the orb) before the 
final finish. The case is simply illustrative of 
the ordinary method of dealing with the cor- 
ners and angles. 
In the act of spinning the spirals the spider 
moves from the circumference toward the cen- 
_, tre, precisely the reverse of the direc- 
ap tion taken when placing in the spiral 
Mamet scaffolding. The rapidity with which 
the spiral line is spun and the pecul- 
iar manner in which the spider’s eight legs ap- 
pear to be intermixed, make it extremely diffi- 
cult to observe and describe the actual method. 
But the process, as it is ordinarily pursued, is substantially as follows: 
The two hind legs are used exclusively to aid the spinning fingers in the 
work of spinning. The other legs are used for locomotion alone. The 
moment one string is fastened at the upper point upon a radius, which 
is done by the application of the spinnerets thereto (see Fig. 79), the 
spider lifts its abdomen, thus of course drawing out after her a thread, 
one end of which is the last point of attachment (x, Fig. 78%) to the 
radius (R 2), and the other the closed spinning fingers. ‘The hind foot 
(4 0) nearest the spinnerets is now bent under and grasps this thread, 
which, as the spider moves, it holds and appears to pull out with great 
rapidity. Next, the inner hind foot (4 i) is bent under and seizes the 
thread, which it holds aloft, stretching it out until it is almost double its 
proper length, as represented in Figs. 79 and 80. If the distance between 
the radii be great, and the spiral string therefore much lengthened, the 
two hind legs will be used alternately several times to draw out the line. 
In the meantime, the outer hind leg, which had first aided the spin- 
nerets in paying out the thread, is reached downward towards the radius, 
Fic. 78. Starting a spiral string. 
