. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. THE TRIANGLE SPIDER: THE ORB SECTOR. 185 three hundred times in a minute, and in so doing they draw out a double line. " The spider moves slowly along the radius until she reaches a point (5) where she can step across to the next radius. While so doing, she ceases to draw out the double line, and carefully keeps it from contact with either of the radii. She then reverses her course and moves along the second radius to a po
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. THE TRIANGLE SPIDER: THE ORB SECTOR. 185 three hundred times in a minute, and in so doing they draw out a double line. " The spider moves slowly along the radius until she reaches a point (5) where she can step across to the next radius. While so doing, she ceases to draw out the double line, and carefully keeps it from contact with either of the radii. She then reverses her course and moves along the second radius to a point (6) nearly under that whence she started. The double line has shortened itself considerably; any slack she draws in, and then turning about, with her head toward the apex, she makes a second attachment with her spinnerets close pressed against the radius. This done, she again hangs from the radius, draws out the spiral line, and ad- vances toward the apex, crosses at 7 to the third radius, returns thereon to 8, and makes a third attachment. She then repeats the same process upon the third radius, and in Fig. 7 is repre- sented (at 9) as %JE] having finished about one-half of the ; The number of crossed lines when the work is completed va- ries, according to Wilder, from six to sixteen. The European Paradoxus, ac- cording to Thorell, spins from sixteen to twenty-two. According to my own count the number is not constant, but the prevailing number is nearly sixteen. I have counted five, fourteen, nineteen, and twenty-two on snares in the same general site. The number is not constant even with the same individual. A female that spun fourteen spirals on one day had nineteen the next; and like differences showed in the other parts of the snare. Evidently there is no mechanical necessity in the constitution of the ara- nead that compels it to a machine regularity of product. These lines are not single threads, covered with viscid beads, as in the case of most Orbweavers,
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
