328 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



weavers. 



The 

 S ider 



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, 

 are 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 E urO p 6j Argyroneta aquatica, weaves in 

 water a bell shaped tent (Fig. 314). within 

 which she dwells, deposits her egg sac, and 

 rears her young. The following observation indicates 

 FIG. 3i4. The i>eii shaped that even in this seemingly unnatural element the 

 rhfwater^pTder^lTnder same general method characterizes the spider's weav- 

 water - ing. Fig. 315 represents a patch of spinningwork 



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

 and drawn by Mr. Underbill. 1 On examining the central part of this 

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

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

 patch at once explained the method by which this close and 

 eyen texture was obtained. They are represented by Fig. 315, c, 

 as ^ ev a PP eare( ^ 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 ncevia wishes to 

 extend the borders of her sheet 



like snare, she proceeds 

 Agalena's ,- 



Method. m the same Way ' carry ~ 

 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 . 



FIG. 315. Highly magnified piece of the Water spider s 

 has been laid down, the Tube- web. a, a, B B, the single original or warp lines ; c, c, c, 



weaver moves backward and for- the banded filaments forming tt 



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



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



1 " Science Gossip," 1875, page 134. 



