INTRODUCTORY LETTER. 9 



that you would declare, upon beholding- some insects, 

 that they had robbed the trees of their leaves to form 

 for themselves artificial wings, so exactly do they 

 resemble them in their form, substance, and vascular 

 structure ; some representiug green leaves, and others 

 those that are dry and withered''. Nay, sometimes 

 this mimicry is so exquisite, that you would mistake the 

 whole insect for a portion of the branching spray of a 

 tree''. No mean beauty in some plants arises from the 

 fluting and punctation of their stems and leaves, and 

 a similar ornament conspicuously distinguishes nume- 

 rous insects, which also imitate with multiform variety, 

 as may particularly be seen in the caterpillars of many 

 species of the butterfly tribe (PapiliomdcB), the spines 

 and prickles which are given as a Noli me tangcre ar- 

 mour to several vegetable productions. 



In fishes the lucid scales of varied hue that cover and 

 defend them are universally admired, and esteemed 

 their peculiar ornament; but place a butterfly's wing 

 under a microscope, that avenue to unseen glories in 

 ne^v worlds, and you will discover that nature has en- 

 dowed tlie most numerous of the insect tribes with the 

 same privilege, multiplying in them the forms'", and di- 

 versifying the colouring of this kind of clothing be- 

 yond all parallel. The rich and velvet tints of the 

 plumage of birds are not superior to Avhat the curious 

 observer may discover in a variety of Lepidoptera; and 

 those many-coloured eyes which deck so gloriously the 

 peacock's tail are imitated with success by one of our 



* Various species of the genera Locusta and Mantis, F. 



b Many species of Phasma, ' De Geer, 1. 1. 3./. 1—34, &c. 



