INTRODUCTION. 49 



ing them to notice, that which arises from contri- 

 buting directly to our interests. 



Hawk-moths and moths possess, of course, many 

 properties in common with butterflies, besides the 

 peculiar consistency of the wings. In the confor- 

 mation of the mouth, mode of propagation, character 

 of the metamorphosis, and many other particulars, 

 there is a general agreement, as may be inferred 

 from their being associated together in the same 

 ordinal division of their class % Instead, therefore, 

 of repeating what has been already said respecting 

 the various organs, their functions, and several 

 other general properties, it will suffice to mention 

 what peculiarities are observable in the tribes in 

 question. Their habits and economy, however, are 

 in many cases so remarkable and interesting, that 

 in order to do that part of the subject any thing 

 bike adequate justice, it will require to be treated in 

 considerable detail. 



They are distinguished from butterflies, among 

 other characters, by having at the base of the under 

 wings, near the anterior edge, a stiff bristle or hair 

 which passes through a hook on the under side of the 

 anterior wings and maintains them when at rest in 

 a horizontal or somewhat inclined position. The 

 most characteristic and destinctive mark of the 

 hawk-moths, the tribe to which we shall first direct 

 our attention, is to be found in the form of the 

 antennae, which increase in diameter from a slender 

 base early to the apex, forming a prismatic, fusi- 

 form club <ind usually terminating in a subulated 



