ARGIOPE AXD HER RIBBONED ORB. 



105 



or Pro- 

 tective 

 Wings. 



lines spun on either side or in front of the orb at the distance of one or 

 more inches from it. In certain positions these wings are thrown on either 

 side of the orb, as represented at Fig. 96, where the web is 

 Fenders hung within a conical or pyramidal mass of cross lines, a retite- 

 larian web, in fact. In this snare both the upper and lower sec- 

 tions of the orb were attached to strong foundation lines set 

 within this mass, which was itself attached to the surrounding 

 foliage. This structure appears to be common as to the upper half of the 

 orb, but the lower part is frequently fastened directly to the foliage or 

 other objects of the site. Such an arrangement adds to the elasticity of 

 the snare, and must materially contribute 

 to its powers of resistance. When the 

 webs of Argiope are spun in such a posi- 

 tion as to expose the spider from either 

 side, the wings are thrown out on both 

 sides, as in the figure. But in a great 

 number of cases only one side is thus de- 

 fended, and it will be found hi such cases 

 that the other side is protected by the 

 foliage against which the orb is spun. 

 These fenders or wings are by no means 

 universal. Indeed, I have examined scores 

 of snares on the same day and for several 

 successive weeks without noticing one ex- 

 ample. The Banded Argiope makes the 

 same kind of protective wings, and I have 

 found several half grown individuals of 

 this species on the seashore of Cape Ann, 

 Massachusetts, whose webs were all thus 

 characterized. Sometimes the fenders are 

 wholly separated from the spinningwork of the orb itself, and are thrown 

 out well upon the flank, and attached to projecting parts of the foliage. 

 They then commonly consist of very strong thick lines resembling those 

 spun for the foundation of the snare. 



The purpose of this outlying spinningwork is probably protective. 

 The scaffolding of crossed lines is thrown over both faces of the orb like 

 wings, chiefly over the middle and upper parts, thus covering the point 

 where the spider domiciles. The wings are several inches distant from 

 the orb. Any large hostile insect or other enemy hovering around 

 the web must first touch the outlying wings, whose agitation 

 telegraphs a warning to the occupant. The detention resulting, 

 trifling as it would be, might yet allow sufficient time, in many cases, for 

 the occupant to escape. The protective wings might even happen to ward 

 off wholly some assailants. On such provisions as this often hangs the 



FIG. 96. Protective wings or fenders of 

 Argiope 's snare. (Side view.) 



Uses of 

 Wings. 



