80 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



manlier covered ; iind so moved around the web until all the corners (at 

 X) were tilled in, leaving the oi)en circular space occu])ied by eight scaffold 

 spirals. 



The lines thus covering the angles are not strictly "spirals" although 

 tliey belong to the spiral space, and liave precisely the characteristics of 

 the true spirals from winch 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 invarialile rule of procedure, for spiders vary their modes. 

 Some start at once u2)on 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. 



^^'''°\W^t;;:y^ 1 I" the act of spinning the spirals the spider 



1 .^^^w^!'*^^'^'^,, moves from the circumference toward the cen- 



I /J'p?yA\ ^ tre, precisely the reverse of the direc- 



1+1 M^l'y ^ Spinning \\qxi taken when placing in the spiral 



xS -^^^ " '^° vyI <^ ■ 1 scaffolding. The rapidity with which 

 -- j- --^-^ . TT the sjiiral line is spun and the pecul- 



-^ ^ ' ""i^ ^^^ manner in which the spider's eight legs ap- 

 pear to be intermixed, make it extremely diffi- 

 FiG.78. starting a spiral string. ^,^^j^ ^^ obscrvc 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. 70), 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. 7S) to the 

 radius (R 2), and the other the closed spinning fingers. The hind foot 

 (4 o) 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, tlie 

 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, 



