. American spiders and their spinningwork. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits . ented by Fig. 315, c, as they appeared under the microscope. They seem to have been produced, as in the cases above described, by the spider erecting or placing, parallel to one another, a series of spinning tubes, which emitted separate and parallel threads, instead of lines directed towards one point. These bands Mr. Underbill supposed to be the product of the anterior spinnerets, while the other two threads, a and B, are emitted by t
. American spiders and their spinningwork. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits . ented by Fig. 315, c, as they appeared under the microscope. They seem to have been produced, as in the cases above described, by the spider erecting or placing, parallel to one another, a series of spinning tubes, which emitted separate and parallel threads, instead of lines directed towards one point. These bands Mr. Underbill supposed to be the product of the anterior spinnerets, while the other two threads, a and B, are emitted by the posterior and middle spinnerets. When Agalena noevia wishes to extend the borders of her sheet like snare, she proceedsAgalenas • ,i Method. ! *^ ^^^^. ^^^i ^^^^ying first various lines be-yond the margin to the desired dis-tance, which lines are stretchedacross the foliage or other surfacethat forms the nest site. Whenthe desired mimber of lineshas been laid down, the Tube-weaver moves backward and for-ward over them, spinning out all the while a stream of silk, at tlie sametime moving her long spinnerets up and down from the surface of the. Fig. 315. Highly magnified piece of the Water spidersweb. a, a, B B, the .single original or warp lines; c, c, c,the banded filaments forming the weft. Science Gossip, 1875, page 134. NEST MAKING : ITS ORIGIN AND USE. 329 frame, by this vertical movement drawing out the thread and beating itback again, thus thickening the weft upon the lines. In this manner asheet of thin texture is rapidly formed, and this, in the course of time, isthickened by a repetition of the same mode of spinning. This is exactlythe method, as I have heretofore shown, pursued by Argiope cophinariain thickening her shield. (See Chapter VI. and illustrations.) It is themanner in which the dome like tents of all the Epeiroid spiders are con-structed. When the method of procedure has been ascertained in onespider, the arachnologist may be assured that he has
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