yo2 Microscopical Essays. 



any thing it is prefled againft, and being drawn out, hardens in the 

 air. The fpider can contract or dilate at pleafure the orifices 

 through which the thread is drawn. The threads unite at a 

 fmall diflance from the body, fo that thofe which appear to us fo 

 fine and (ingle, are notwithstanding compofed of five joined to- 

 gether, and thefe are many times doubled when the web is in 

 formation. 



The gnat is a beautiful objecl; for the microfcope. We have 

 already noticed the curious manner in which they difpofe their 

 eggs upon the furface of the water. Thefe, as they come to ma- 

 turity, fink deeper. There is no fpecies of infect more trouble- 

 fome to mankind than the gnat : others give more pain with their 

 flings, but it is only by accident we are flung by them ; but the 

 gnats third for our blood, and follow us in whole companies for 

 it. There are many marmy places in our country, where the 

 legs and arms of the inhabitants are kept fwelled all the fummer 

 by the biting of thefe infects : in many other countries they are 

 yet more troublefome than with us. It is one of thofe infects 

 which pafs through two ftates of life, feemingly quite oppofedto 

 each other ; in one condition fwimming in the water like fifh, in 

 the other becoming like the birds, inhabitants of the air. 



From the egg proceeds the larva, in which ftate it is moft 

 happily fuited to (hew the feveral operations of life; for a 

 moderate magnifying power will difcover what paffes within it's 

 tranfparent body. It has a large fcaly head, with two large an- 

 tennas, befides feveral hairy parts, and articulated briftles near 

 the mouth, which are in continual motion. If the worm be dif- 

 fered, the feet of the gnat may be found folded up in the 



divifions 



