LECTURE IX. 
VVE are now to direct our attention to a large 
and various class of beings known by the title 
of Insects. The characters by which Insects are 
distinguished from other animals are the following. 
First, they are furnished with several feet ; never 
fewer than six, and sometimes with a great many. 
Secondly their flesh, or the muscular part of their 
frame, is aflixed to the internal surface of their 
skin, which is generally of a somewhat tough or 
strong substance, and in many even hard or horny. 
Thirdly, they breathe, not in the usual mannOr of 
the generality of tlie larger animals, by lungs, or 
by gills, but by a sort of spiracles or breathing- 
holes, situated at certain distances along each side 
of the body ; and lastly, the head is generally fur? 
