328 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



^■.4:;.y^^iii^^sA-#;5^-.- ■■■;■ • 



If we turn to the Tubeweavers we find a varied and interesting field 

 of spinning industry in the making of snares, nests, and cocoons. In all 

 of these it may be confidently said that the methods, as far as known, 

 ..<-^<iW^^:ify.--- ^^^® substantially the same as those described as prevail- 



ing in other tribes. A few illustrations show this fact. 

 The interesting and well known water spider 

 Methods q£ Europe, Argyroneta aquatica, weaves in 

 weavers ^^^^^ ^ ^^^^ shaped tent (Fig. 314), within 

 which she dwells, deposits her egg sac, and 

 rears her young. The following observation indicates 

 Fig. 314. The bell shaped that cvcu ill this Seemingly unnatural element the 

 Thf water'^sS'de^^uncier ^^^'^^^ general method characterizes the spider's weav- 

 ^^**'^- ing. Fig. 315 represents a patch of spinning work 



made by this water spider upon a glass within which she was confined, 

 and drawn by Mr. Underbill, i On examining the central part of this 

 patch, it appeared, both to the naked eye and to the microscope, like 

 a piece of tli^ spider's cocoon. Certain broad threads at the edge of the 

 patch at once explained the method by which this close and 

 55® even texture was obtained. They are represented by Fig. 315, c, 



Spider ^^ ^^^^y 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 j)roduct 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 proceeds 

 Agalena's • ,-, 



Method. !^^ ^^'® ^^^^ ^^^3^' ^^^'^3^- 

 ing first various lines be- 

 yond the margin to the desired dis- 

 tance, which lines are stretched 

 across the foliage or other surface 

 that forms the nest site. When 

 the desired number of these lines 

 has been laid down, the Tube- 

 weaver moves backward and foi-- 

 ward over them, spinning out all the while a stream of silk, at the same 

 time moving her long spinnerets up and down from tlie surface of the 



Fig. 315. Highly magnified piece of the Water spider's 

 web. a, a, B B, the single original or warp lines ; c, c, c, 

 the banded filaments forming the weft. 



J " 



Science Gossip," 1875, page 134. 



