CHAPTER XT. 



PROCURING FOOD AND FEEDING. 



The Orbweaver's snare is its tool for trapping insects. It is a notable 

 fact in the history of lower animals, that there is at least one order con- 

 taining a large group of species which possess the power, other- 

 Pood ^jgg ^Yie almost exclusive gift of man, to procure food by the 

 rp , medium of manufactured implements. The nearly universal 



habit of natural life is to imbibe nutriment directly, or to secure 

 it wholly by means of the feet or mouth or other prehensile organs. The 

 Wandering spiders fall into the general course of nature, and seize their 

 food directly. The Sedentary spiders form an exception to this rule. 



It is, of course, an interesting speculation how this remarkable habit 

 originated, and how it came about that such a marked exception sliould 

 exist in certain tribes of a natural order whose remaining tribes are want- 

 ing therein; but Nature thus far has yielded no light upon the subject. 

 As far as we are able to judge from fossil spiders, the structural differences 

 between such families as Epeirids on the one hand, and the Lycosids 

 and Attoids on the other, have remained unchanged from the first appari- 

 tion of spider life. It is a fair inference that the functional differences 

 have also always existed ; that Epeirids have always captured their prey 

 through the media of manufactured tools or snares, and that the Lycosids 

 have stalked their prey and secured their food without any intervening 

 instrument. 



It has already been shown how well adapted an orbweb is for its chief 

 purpose. Its combined strength and elasticity, its admirable arrangement 

 for the free motion of the spider, its location and characteristics so well 

 adapted to arrest the flight of insects, and its armature of viscid beads so 

 completely suited to retain and disable the arrested victims — these all form 

 an implement of tremendous facility to the aranead for procuring its nat- 

 ural food. The spider when ensconced within its nest holds by 

 ^"^ ^^ its claws to the tense trapliae, and thus keeps its snare taut. 

 'When it is suspended at the hub the eight legs, stretched out 

 and grasping points of the radii which command the entire snare, enable 

 the spider at any time to contract its outlying lines around the centre, 

 thus producing the same degree of tension. 



(247) 



