232 NATURAL HISTORV. [cH. XlV, 



. But, besides these eight legs, spiders have two 

 others inserted in the fore-pcirt of their body, and 

 which may be called their arms, since they do not 

 use them for transferring themselves from one place 

 to another, but only for holding and turning their 

 prey. But although thus formidably equipped with 

 weapons of attack, the spider would still be unsuc- 

 cessful in providing for its wants, if not furnished 

 with the means of constructing an ambuscade to 

 surprise its victim. The spider has no wings to 

 assist in the pursuit, while its prey is furnished with 

 those organs as the means of escape. This would 

 prove a fatal disadvantage, if the insect had not been 

 furnished with a stock of material, which it can 

 spin into a thread, and employ in constructing a web 

 or snare, which it spreads in the open air to inter- 

 cept the prey which is continually passing. Instinct 

 informs the spider when the proper season has ar- 

 rived for weaving this snare: which is invariably 

 begun when its prey first receives its birth. When 

 the web has been completed, the insect retires into 

 obscurity behind its net, where it patiently awaits 

 for a victim, to which it has rendered itself invisible. 

 The manner of constructing this web is extremely 

 artful and ingenious. All spiders are furnished, at 

 the extremity of their belly, with four or six teat- 

 like protuberances or spinners. Each of these pro- 

 tuberances is furnished with a multitude of tubes, so 

 numerous and so exquisitely fine, that, according to 

 Reaumur, a space not much bigger than the pointed 

 end of a pin is furnished with a thousand of them. 

 Hence, from each spinner proceeds a compound 

 thread. At the distance of about one-tenth of an 

 inch from the point of the spinners these threads 

 again unite, and form the thread which we see, and 

 whi(;h the spider makes use of in forming its web. 

 Thus, a spider's thread, even when so fine as almost 

 to elude our senses, is not a single line, but a rope 

 composed of at least four thousand strands. Of 



