DO INTRODUCTION. 



body being bent upwards into a loop or arch. Every 

 progressive movement is effected by a repetition of 

 the same manoeuvre, and the ground is thus traversed 

 by regular and measured steps, each of which is 

 nearly equal to the length of the insect's body. 

 These peculiar attitudes have caused the caterpillars 

 to be termed loopers and geometers ; and as they 

 possess the power, from the great strength of their 

 muscles, of fixing themselves by the hinder legs 

 to a branch, and stretching out the body stiffly 

 into the air, a position which they often maintain 

 immovably for a length of time, they are likewise 

 known by the name of surveyors. The kind of 

 locomotion just described is best exhibited by such 

 larvae as have only two or four prolegs, but it is 

 likewise seen in those that have six, and occasionally 

 even in species furnished with the full compliment 

 of ventral legs. 



In the colour of their bodies these caterpillars 

 are as greatly diversified as in their other properties. 

 Such as live in the interior of trees, and in places 

 where they are little exposed to the influence of 

 light, are frequently of a dingy white or yellowish 

 brown colour; but the kinds which frequent the 

 foliage of plants, constituting by far the largest 

 proportion, are often ornamented with the most 

 vivid and varied tints. Reaumur asserts that they 

 exhibit examples of every known colour, besides 

 an infinite variety of shades, of which it would be 

 difficult to find the like elsewhere. Some are of 

 one uniform hue, but the majority are adorned 



