338 INSECT ARCHITECTURE. 



It is well known in our manufactures, particularly in 

 rope-spinning, that in cords of equal thickness those 

 which are composed of many smaller ones united 

 are greatly stronger than those which are spun at 

 once. In the instance of the spider's thread, this 

 principle must hold still more strikingly, inasmuch 

 as it is composed of fluid materials that require to be 

 dried rapidly, and this drying must be greatly 

 facilitated by exposing so many to the air separately 

 before their union, which is effected at the distance 

 of about a tenth of an inch from the spinnerets. In 

 the following figure each of the threads represented 

 is reckoned to contain one hundred minute threads, 

 the whole forming only one of the spider's common 

 threads. 



Aiinglethread of a Spider, (neatly magnified, w that, fir the mall 

 apace represented, the lines are shown us parallel, 



Leeuwenhoeck, in one of his extraordinary micro- 

 scopical observations on a young spider not bigger 

 than a grain of sand, upon enumerating the thread- 



