18 DR. BRACKENRIDGE CLEMENS' LETTERS. 



and method of observation of the various orders of insects. 

 The portion referring to Lepidoptera was written by myself, 

 and enters fnlly into the subject.* For the purpose of dis- 

 tributing it widely over the country, it "will appear in the 

 first place in the Smithsonian Report for the present year, 

 and a large number of the article itself will be distributed by 

 mail as a circular, the number of reports not being sufficient 

 to enable us to supply all the various points of our large 

 territory. 



The effect of this, however, will be seen in the future, and 

 I have but little doubt that the future of " Entomology in 

 America" will be a bright one. I have but just completed a 

 Synoptical Paper on the Sphingidce of the North American 

 Continent, with descriptions of nearly 100 species. Of course 

 all these are not my own, for I have been compelled to ex- 

 tract many from Mr. Walker's List of the British Museum. 

 It is intended, however, only as a " basis" on which the 

 information so much needed respecting species in our country 

 can be conveniently worked up. It contains some new fea- 

 tures on which you must decide when you see it. Now you 

 must not smile when I say, that I have added to it an Essay 

 on the Classification of the Order or rather of the Heterocera. 

 You must remember that here we are untrammelled by any 

 established reference books, which tie down minds to par- 

 ticular ideas. With us every thing has yet to be done, and 

 in what I have written I have endeavoured to treat the 

 subject philosophically and with reference to what I regard as 

 natural. You will doubtless find many ideas advanced with 

 which you will be inclined to take issue, and if they are 

 shown to be erroneous it will simply be a source of pleasure 

 and satisfaction to me. This paper will be published during 

 the summer in the Journal of the Academy of Natural 

 Sciences in Philadelphia, and will be distributed to students 

 almost gratuitously. I shall have the honour to send you an 

 early copy of it. 



I have, however, something else to tell you that will perhaps 



* " Instructions for Collecting Lepidoptera." Smithsonian Report for 

 1858, pp. 173—200. II. T. S. 



