406 FOOD OF INSECTS. 



still finer. It follows, therefore, that above sixteen 

 thousand millions of the finest threads which issue from 

 such spiders are not together thicker than a human 

 hair! Of such tenuity it is utterly beyond the power 

 of the imagination to conceive : the very idea over- 

 whelms our faculties, and humbles us under a sense of 

 their imperfection. — Of the probable accuracy of this 

 calculation you may any day in summer convince your- 

 self, by taking one of the largest field spiders, (as Aranta 

 Diadema, L.), and after pressing its abdomen against a 

 leaf or other substance, so as to attach the threads to 

 the surface — the same preliminary step which the spi- 

 der adopts in spinning — drawing it gradually to a small 

 distance. You will plainly perceive that the proper 

 thread of the spider is formed of fonr smaller thread?, 

 and these again of threads so fine and numerous, that 

 there cannot be fewer than a thousand issue from each 

 spinner; and if you pursue your researches with the 

 microscope, you will find that precisely the same takes 

 place in the minutest species that spins. — You will in- 

 quire what can be the end of machinery so complex? 

 One probable reason is, that it was necessary for dry- 

 ing the gum sufficiently to form a tenacious line, that 

 an extensive surface should be exposed to the air; 

 which is admirably effected by dividing it at its exit 

 fi'om the abdomen into such numerous threads. But 

 the chief cause, perhaps, is the occasion (hereafter to be 

 adverted to) which the spider sometimes has to employ 

 its threads in their finer and unconnected state before 

 they unite to form a single one. — The spider is gifted 

 by her Creator with the power of closing the orifices 

 of the spinners at pleasure, and can thus, in dropping 



