THE ANIMAL KINGDOM. 187 



work of the insect, too, exhibits a remarkable complication ; 

 for, fine as it is, it results from the union of many distinct 

 threads. It is produced by four or six teats, or spinnerets, 

 situated at the extremity of the abdomen, and the silky 

 matter itself issues by a sieve-like apparatus ; each sieve 

 containing, according to Bonnet, more than a thousand 

 holes. As the filaments are projected outwards, they agglu- 

 tinate together in such a manner that each thread is com- 

 posed of at least 4000, and sometimes of 6000, fibres, and 

 yet Leuwenhoeck affirms that it is so slender as to require 

 4,000,000 to make up a silk thread as thick as one of the 

 hairs of one's beard. 1 



The threads of some exotic species possess a much greater 

 power of resistance than we observe in ours. Travellers 

 relate that in equatorial countries spider-webs are seen 

 strong enough to arrest humming-birds as a net would, and 

 it has even been said that a man only breaks them with 

 some difficulty. 



The silk of our spiders is always of a dirty gray, but in 

 tropical regions the color varies to a certain extent. Some 

 of these insects produce different colored threads, which 

 they interlace with admirable skill. Some are red, others 

 yellow, others again black, and with all these they form a 

 three-colored fabric. 



Industrial art has vainly attempted to utilize the silk of 

 the spider ; but that produced by the European species has 

 so little power of resistance that it has never been used to 



1 Kirby and Spence say that the holes of the threads are so fine and so 

 crowded together that there are 1000 of them in the space covered by the point 

 of a needle. 



