MECHANICAL FUNCTIONS. 



by the cord stretched between them. If it proves to 

 be some luckless fly, which has caused the alarm, the 

 voracious spider mounts the cord, and in another 

 instant may be seen tying the legs, and wings of its vic- 

 tim, with the utmost eagerness and art, so as to prevent 

 the possibility of escape. Having thus secured its prey, 

 it sucks its blood at leisure, and then retires and waits for 

 another haul. 



184. If craftiness, ingenuity, and contrivance, are not ex- 

 hibited in such proceedings as these, we know not where 

 to find them in the animal kingdom. Any one by watch- 

 ing a common house-spider may convince himself of the 

 truth of our statement. 



185. The ingenuity with which spiders contrive to es- 

 cape when surrounded by water, is sometimes highly curi- 

 ous and interesting. Mr. Kirby placed a large field-spider 

 upon a stick about a foot long set in a vessel of w r ater. 

 After fastening its thread at the top of the stick, it crept 

 down the side until it came to the water, then immedi- 

 ately swinging from the stick which was slightly bent, 

 it climbed again to the top. This it repeated many 

 times, still finding its retreat cut off, and no means of 

 escaping in that manner. At length it let itself down 

 from the top of the stick, not by a single thread, but by 

 two, each distant from the other about the twelfth of an 

 inch, guided, as usual, by one of its hind feet, one of the 

 threads being apparently smaller than the other. When 

 it had suffered itself to descend nearly to the surface of 

 the water, it stopped short, and by some means not 

 apparent, broke off close to the spinners, the smallest 

 thread, which still adhering to the top of the stick, float- 

 ed in the air, and w r as so light as to be moved by the 

 slightest breath. This thread catching on an object at a 

 little distance, the spider employed it as a bridge to n. ake 

 its escape. 



186. But the ingenuity and resources of this tribe oi 

 insects are so well known, that we will not multiply 

 more instances. 



187. Ingenuity of the Caddis-Worm. A little insect. 

 or worm common in fresh-water brooks, called the caddis- 

 worm, and well known to anglers, builds for itself a 



