38 HISTORY OF 



their banks, especially under shady trees, and ge- 

 nerally in swarms of several together. 



The Common Water Fly also breeds in the 

 same manner with those above mentioned. This 

 animal is by some called Notonecta, because it 

 does not swim in the usual manner, upon its 

 belly, but on its back ; nor can we help admir- 

 ing that fitness in this insect for its situation, as 

 it feeds on the under side of plants which grow 

 on the surface of the water ; and therefore it is 

 thus formed with its mouth upwards, to take its 

 food with greater convenience and ease. 



We may also add the Water Scorpion, which is 

 a large insect, being near an inch in length, and 

 about half an inch in breadth. Its body is nearly 

 oval, but very flat and thin, and its tail long and 

 pointed. The head is small, and the feelers ap- 

 pear like legs, resembling the claws of a scorpion, 

 but without sharp points. This insect is generally 

 found in ponds, and is of all others the most ty- 

 rannical and rapacious. It destroys, like a wolf 

 among sheep, twenty times as many as its hunger 

 requires. One of these, when put into a basin of 

 water in which were thirty or forty worms of 

 the libellula kind, each as large as itself, destroy- 

 ed them all in a few minutes, getting on their 

 backs, and piercing with its trunk through their 

 body. These animals, however, though so for- 

 midable to others, are nevertheless themselves 

 greatly overrun with a little kind of louse, about 

 the size of a nit, which very probably repays the 

 injury which the water scorpion inflicts upon 

 others. 



