340 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



than almost any other of our native Orbweavers, unless, indeed, their pre- 

 ferred site within the shaded walks of groves and woods may be consid- 

 ered a protection. 



Gasteracantha, with its strongly developed spines, has much the same 

 habit as Acrosoma, but the spines appear to be wanting in the young of 

 this genus, the very age, one would think, at which they are most needed. 

 However, the young of Gasteracantha, at least with numerous .specimens 

 sent from the Pacific coast, are almost black in color, a feature which must 

 certainly be regarded as protective, if bright colors best invite the oljserva- 

 tion of enemies. 



On the whole, the conclusion seems to be justified that many .spiders 

 which appear to be more exjiosed to enemies by reason of bright colors 

 or greater size, possess special variations in industry and habits that in 

 some degree are protective; but there are so many apj^arent exceptions to 

 this, which ro(iuire more careful study, that no generalization can now be 

 warranted. 



If we come finally to consider the bearing of what has been called 



"warning coloration" upon spiders, there is little to l)e said. In the case 



of those numerous species which belong to the Wanderers, the 



„ , " " colors cannot be considered as warning, but, as we have seen, are 

 Colors. • . oi 1 ■ T 1 • 



rather protective. As to Sedentary species, I cannot think of any 



animal that would avoid them as inedible on account of their color, or of 

 any influence that their color could have in warning insects of danger. 

 In point of fact, the colored spiders appear to be as delicate mor.scls to 

 those tliat feed upon them as any otlier sort, and they are just as fre- 

 quentl)', and perhaps I may say even more frequently, though by no 

 means exclusively, selected for such purposes. 



That a warning should lie conveyed to insects by the color of a spider 

 at the centre of its web seems to mo wholly imaginary, since Sedentaiy 

 spiders do not capture food directly, but by means of their manufactured 

 trapping instruments. Indeed, I have little faith in the opinion that in- 

 sects are capable of experiencing anything like a warning, from color or 

 other causes, against the presence of spiders. I feel sure that 

 Insects ^j,jg jg ^jjg gjjgg -vvith flies, the insects which perhaps more than 

 „ any other form the staple food of the various aranead tribes. I 



SCIOUS oi -^ ^ 



Danger. I'^ive often been witness of the ab.solute indifference of various 

 species of flies to the presence of spiders. One remarkable ex- 

 ample is recorded (Vol. L, page 256), in which, during an entire season, 

 I observed numbers of a little black Diptera settling and feeding upon 

 the carcasses of large blue bottle and house flies which had been trapped 

 and trussed within the orbs of Argiope. In several cases these little creat- 

 ures were observed stationed within the open jaws of their gigantic enemy, 

 sipping juices which the spider was expressing from the fly on which she 

 was feeding. 



