Microscopical Essays. 



a mare, who was feparated from the reft, making lefs noife than 

 before, and here it was more fuccefsful ; it pa fled under the tail, 

 and by earning an itching near the anus, forced the mare to pufh 

 out the edge of the interline, to open it, and then to enlarge the 

 opening ; the fly profited by this opportunity, and depofited it's, 

 eggs in the fold of the inteftine ; in a little time the mare became 

 almoft furious, and was agitated in the moft violent manner for a 

 quarter of an hour, when fhe began to grow more eafy. 



Nearly allied to the preceding are the following curious obfer- 

 vations of an ingenious naturalift on the ichneumon fly. " As I 

 was obferving, fays he, one day fome caterpillars which were 

 feeding voluptuoufly on a cabbage-leaf, my attention was at- 

 tra£led towards a part of the plant, about which a little fly was. 

 buzzing on its wing, as if deliberating where to fettle: I was fur- 

 prized to fee the herd of caterpillars, creatures of twenty times 

 it's fize, endeavouring in an uncouth manner, by various contor- 

 tions of the body, to get out of it's way, and more fo, whenever 

 the fly poifed on the wing as if going to drop ; at length the 

 creature made it's choice, and feated itfelf on the back of one of 

 the largefl and faireff of the clufter; it was in vain the unhappy 

 reptile endeavoured to diflodge the enemy. If the caterpillar 

 had fhewn terror on the approach of the fly, it's anguifh at inter- 

 vals now feemed intolerable, and I foon found that it was in con- 

 fequence of the ftrokes, or wounds, given by the fly. At every 

 wound the poor caterpillar wreathed and twirled it's whole frame,, 

 endeavouring to difengage itfelf, by ftiaking off the enemy, 

 fometimes aiming it's mouth towards the place ; but it was all in 

 vain, it's little but cruel tormentor kept it's place. When it had 

 inflicled thirty or forty of thefe wounds, it took it's flight with a 

 4 vifible 



