52 A FEW WORDS ABOUT MOTHS. 



the perfect insect can be identified and its form sketched how 

 much was gained I A truthful and circumstantial biography, in 

 all its relations, of a single insect has yet to be written ! 



We should also apply our knowledge of the larval forms of 

 insects to the details of their classification into families and gen- 

 era, constantly collating our knowledge of the early stages with 

 the structural relations that accompany them in the perfect state. 



The simple form of the caterpillar seems to be a concentra- 

 tion of the characters of the perfect insect, and presents easy 

 characters by which to distinguish the minor groups ; and the 

 relative rank of the higher divisions will only be definitely 

 settled when their forms and methods of transformation are 

 thoroughly known. Thus, for example, in two groups of the 

 large Attacus-like moths, which are so amply illustrated in Dr. 

 Harris's " Treatise on Insects injurious to Vegetation ; " if we 

 take the different forms of the caterpillars of the Tau moth of 

 Europe, which are figured by Duponchel and Godard, we find 

 that the very young larva has four horn-like processes on the 

 front, and four on the back part of the body. The full grown lar- 

 va of the Regalis moth, of the Southern and Middle states, is 

 yery similarly ornamented. It is an embryonic form, and there- 

 fore inferior in rank to the Tau moth. Multiply these horns over 

 the surface of the body, lessen their size, and crown them with 

 hairs, and we have our lo moth, so destructive to corn. Now 

 take off the hairs, elongating and thinning out the tubercles, 

 and make up the loss by the increased size of the worm, and we 

 have the caterpillar of our common Cecropia moth. Again, 

 remove the naked tubercles almost wholly, smooth off the 

 surface of the body, and contract its length, thus giving a 

 greater convexity and angularity to the rings, and we have 

 before us the larva of the stately Luna moth that tops this royal 

 family. Here are certain criteria for placing these insects 

 before our minds in the order that nature has placed them. 

 "We have certain facts for determining which of these three 

 insects is highest and which lowest in the scale, when we sec 

 the larva of the Luna moth throwing off successively the lo and 

 Cfecropia forms to take on its own higher features. So that 

 there is a meaning in all this shifting of insect toggery. 



This is but an example of the many ways in which both 

 pleasure and mental profit may be realized from the thoughtful 

 study of caterpillar life. 



