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 circular space occupied by eiglit 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 



— -.■■- ^^ ■ 1 final finish. The case is simply illustrative of 



/f ^<r '^^^ ordinary method of dealing with the cor- 



I (1 y ___^^^__ I 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- 

 uh M^J^y Spnimng- ^^^^-^ taken when placing in the spiral 



3gl :u^^ "'''^° vvl s ■ 1 scaffolding. The rapidity with which 



• •■i-.«' > - " rX- the spiral line is spun and the pecul- 



"rp ^ ' --4'g iar manner in which the spider's eight legs ap- 

 pear to be intermixed, make it extremely diffi- 

 tarting a spiral string. ^^^ ^^ obscrvc and dcscribe the actual method. 



But the process, as it is ordinarily pursued, is substantially as follows : 

 Tlie 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. 7'8) 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 iimer 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 ]je great, and the spiral string therefore much lengthened, the 

 two hind legs will be used alternately several times to draw out the line. 



In tlie meantime, the outer hind leg, which had first aided the spin- 

 nerets in ])aying out the tliread, is reached downward towards the radius. 



