92 THREE KINGDOMS. 



pay letter postage. One or two fine specimens are always 

 more acceptable than several inferior ones. No propo- 

 sitions for exchange can be noticed in our paper, except- 

 ing from subscribers, or from members of the A. A. 

 For this, among other reasons, it is necessary for us to 

 keep a full register of all members, and names of new 

 members should always be sent us at once- 



Whenever any one writes proposing an exchange, 

 courtesy requires him to enclose a stamp for reply. 

 Kequests of this nature should always be promptly an- 

 swered. Aim to give rather more than you receive. A 

 grasping spirit of trade is utterly foreign to the nature 

 of a true scientist. 



