12 LIST OF BRITISH ENTOMOLOGISTS. 



But independently of this use of the list of Entomologists, 

 it may also be extensively useful by enabling those who are 

 far advanced beyond being mere beginners, to obtain some 

 of those local species of which their collections are at present 

 deficient. The Entomologist who lives in Sussex will never 

 meet with Erebia Blandina, though he collect for fifty 

 years; the Entomologist located in Argyllshire may be 

 equally certain he will never there meet with Limenitis Si- 

 billa. Now if the one collector meet with more Sibilla 

 than he can use, he may as well give them away; and if the 

 Argyllshire Entomologist meet with more Blandina than 

 he wants, he will, in like manner, be no poorer from parting 

 with what is a superfluity with him — yet each will be a 

 gainer by the exchange. 



By the word exchange, I do not mean that each obtains an 

 exact equivalent for the hypothetical money value of the speci- 

 men parted with. A duplicate is something we do not want, 

 its value to us is 0; if we attempt to bargain with a cor- 

 respondent what he shall give us in return for our duplicate, 

 we become hucksters and petty tradesmen. Many a young 

 Entomologist, to my certain knowledge, thinks that by ex- 

 changing insects is meant parting with his duplicates for 

 others of equal value; and therefore that in opening a cor- 

 respondence by saying, " I have got so and so, what will you 

 give in exchange for it," he is merely acting according to 

 the customary practice of most of our distinguished Entomo- 

 logists, but in this he labours under a great mistake — 



" Freely ye have received, freely give ;" 



and he will find that the practice is to give away duplicates 

 to others who may be in want of the respective species, 

 without any stipulation with regard to exchanges. 



Directly he begins to " drive a bargain," he gets a bad 

 character, and " mercenary," " greedy," " stingy," are a few 



