PEEFACE. 9 



ferent parts of the body in the Lepidoptera, although 

 the hair and scales covering the body and wings 

 must be removed in order that the shape of the 

 pieces making up the thorax and head, and the 

 course of the veins, be clearly observed. An ex- 

 cellent method of taking the colouring-matter out 

 of the scales of the wings, rendering them perfectly 

 transparent, has been discovered by Mr. George 

 Dimmock ; and my friend Professor C. H. Fernald 

 has explained the method employed by him in 

 mounting the prepared wings as microscopic objects 

 with such success. A knowledge of the structure 

 of the legs is of importance in the classification of 

 the Noctuidae, in order to locate the species gene- 

 rically ; but this can be observed with a good lens 

 (I have used a half-inch on a binocular stand), and 

 generally without any denuding, although the arma- 

 ture of the front tibiae is sometimes concealed by 

 the vestiture. 



The growth of the Moths may be divided into 

 the several stages of egg, caterpillar, chrysalis, and 

 imago or perfect insect, as these are severally easily 

 observed by us. Yet the life of the individual very 

 gradually proceeds, despite the apparent suddenness 

 of the transformations it undergoes. From another 

 point of view we may consider the life of the Moth 

 as falling into two periods — its immature existence, 

 and the final mature state in which it is able to re- 

 produce its kind. The egg, caterpillar, and chrysalis 

 mark epochs in its immature condition, the two 

 latter stages not being as completely defined in 



