HABITS OF SPIDERS. 



able, an instant is sufficient for this purpose. The sedentary 

 Aranei'daB (those which do not go in pursuit of their prey) weave 

 with these threads various structures which they use as snares to 

 entrap the insects necessary for their nourishment; sometimes 

 these webs are so strong as to arrest small birds, but generally 

 they are very delicate. After constructing it, the animal places 

 himself in its centre or at the bottom of its web, sometimes in a 

 particular habitation situated near one of its angles ; as soon as 

 an insect is caught in the snare, he rapidly approaches his prey, 

 and makes every effort to pierce it with a kind of venomous dart 

 with which the mandibles are furnished, and distils into the wound 

 a poison which acts very promptly ; when the insect offers too 

 strong resistance, or. when it would be dangerous for the spider 

 to contend with it, he retires for a moment to wait till its powers 

 are exhausted, or until it is more entangled ; or if there is nothing 

 to fear, he hastens to bind it by throwing threads of silk around 

 its body, which sometimes envelope it entirely, forming a cover- 

 ing so thick as to remove it from sight. 



19. The female Aranei'da3 also employ their silk in construct- 

 ing bags or cocoons to contain their eggs. 



20. Those white and silky flocculi, 

 which are seen floating on the air, in 

 foggy weather, in the spring and au- 

 tumn, are composed of silk of this kind 

 produced by various young Aranei'da3 ; 

 they are principally the strong threads 

 which serve to attach the corners of 

 the web, or those which compose the 

 chain, and, having become heavier by 

 the action of the moisture, sink, ap- 

 proach each other, and finally form 

 little pellets. 



21. Most Arach'nidans of this divi- 

 sion are more or less venomous ; the 

 bite of some large species in hot coun- 

 tries is sometimes fatal to man ; and in 

 our climate, a spider of moderate size 

 will kill a fly in a few minutes by in- 

 flicting a single wound. 



22. The MYGALES (/#. 57), which 



Explanation of Fig. 57. The mygalc or mason spider ; a, the cephalo- 

 thorax ; ft, the abdomen ; p, the palpi. 



19. How do the female aranei'dae take care of their eg-g-s ? 



20. What are those white flocculi sometimes seen in foggy weather ? 



21. Are spiders venomous? 



22. What are the characters of Mygales ? What are the habits of Mason 

 Spiders ? 



Fig. 57. MYGALE. 



