8 PEEFACE. 



latter only to be observed by the microscope. The 

 latter class are of the most value ; yet, for con- 

 veuieiice, some of the former may be considered 

 valid. I discuss, therefore, in this Essay merely 

 the external characters, the sorting of individuals 

 into " species," and the literature of the North- 

 American Noctuidse. The method of classifying 

 by mere appearance can lead to no scientific result ; 

 yet, aufond, this is the method employed by English 

 lepidopterists, of whom the extreme example was 

 Mr. Walker, and the best, perhaps, Mr. Doubleday. 

 There must l)e a radical change in this procedure, 

 of which we in the United States are the legatees, 

 and show that we are, when we " lump " the genera 

 allied to Hesperia or Tludryas. The microscope 

 must be thoroughly used at every step, and then 

 the dissecting-needle. We are yet employed merely 

 in getting our cabinets into order ; and the real 

 results we are to obtain, the connexions of the 

 Noctuidse with the chain of living organisms, are 

 ahead of us in time. 



The study of Nature and the collection and ex- 

 amination of objects of Natural History is a favourite 

 occupation of our race. Eor those who have patience 

 and some manual dexterity, the formation of a col- 

 lection of Butter jflies and Moths will give pleasure 

 and instruction. It is better if it be undertaken iu 

 connexion with a study of the structure and habits 

 of the insects, viewing them in their relation to 

 the rest of animated Nature and their immediate 

 surroundings. It is not difficult to become ac- 

 quainted with the external appearance of the dif- 



