s68 



Microscopical Essays. 



The gnat, the ephemera, the phryganea, the libellula, hover 

 over the water all day to drop their eggs, which are hatched in 

 the water, and continue there all the time they are in the larva 

 form. The mafs formed by the gnat refembles a little veffel fet 

 afloat by the infect ; each egg is in the form of a keel ; thefe are 

 curioufly connected together. The gnat lays but one egg at a 

 time, which {he lays upon the water in a very ingenious and fim- 

 ple manner ; {he ftretches her legs out, and crofles them, thus 

 forming an angle to receive and hold the firfl; egg ; a fecond egg 

 is foon placed next the firft ; then a third, and fo on, till thebafe 

 is capable of fupporting itfelf. The fpawn of this infect is fome- 

 times above an inch long, and one-eighth of an inch in diameter, 

 and tied by a little ftem, or ftalk, to fome flick or ftone. Some- 

 times they are laid in a fingle, fometimes in a double fpiral line ; 

 fometimes tranfverfely. Many moths cover their offspring with 

 a thick bed of hair, which they gather from their own body ; 

 while others cover them with a glutinous compofition, which, 

 when hard, protects them from moiflure. rain, and cold. The 

 gall flies, it has been already obferved, know how to open the 

 nerves of the leaves, to depofit thus their eggs in a place which 

 afterwards ferves them for a lodging, and a magazine of food. 

 The folitary bees and wafps prepare an habitation for their little 

 ones in the earth/ placing there a proper quantity of food for 

 them, when they proceed from the egg. The voracious and 

 cruel fpider is attentive and careful of it's eggs ; the wolf fpider 

 carries them on it's back in a little bag formed of it's filk ; it can- 

 not be feparated from them but by violence, and exhibits the 

 mofl marked figns of uneafinefs when deprived of them : a cir- 

 cumftance the more remarkable, as they love to deftroy each 

 other, and even carry on their courtfhips with a diffidence and 

 4 caution 



