378 



OF THE WOOD-LOUSE AND ITS VARIETIES. 



The wood-louse, which exceeds every other in size, 

 is a quarter of an inch broad, and above half a one in 

 length ; if found about dung-hills it is a livid black, 

 but if in drier places the colour resembles that of an 

 ass. When touched it rolls itself up like a ball ; and it 

 has two feelers, and fourteen feet. It is generally 

 found amongst rotten timber; and the young, like 

 those of the other kind, are produced from eggs. These 

 animals are allowed to be useful in medicine; and, 

 when impregnated with a saline quality, have produced 

 astonishing effects. 



OF THE MANOCULUS, OR WATER-FLEA. 



This little animal, if observed without the micro- 

 scope, appears to possess but one eye, for the head is 

 so small that they are joined together, and placed at the 

 extremity of the trunk; and the size never exceeds 

 that of the common flea. Their colour resembles that 

 of blood ; and they frequently float in such numbers 

 upon the surface of the water, as to give it an appear- 

 ance of a saniiuinarv stream. 



The branching arms of this insect deserve to obtain 

 attention, as by their assistance they wave upon the 

 element from which it derives its name, as a bird moves 

 in any direction with its wings. It is produced from 

 an egg upon the surface of the water ; and, like most 

 other insects, exchanges its skin. 



