84 THREE KINGDOMS. 



hanced by placing each by itself in a neat pasteboard 

 tray, or on a block of wood; and the label can then 

 be attached to the beveled edge of the block. 



As just explained, the ideal plan is for the student 

 to collect his own specimens; and it may be fairly 

 said that for the collector specimens have an interest 

 and value beyond what they would otherwise possess. 

 It is, however, often impracticable to obtain suitable 

 material in this way for a general course of study. 

 The best plan then is, not to fall back on the books 

 and dispense with the specimens, but to buy them. 

 Those desiring to purchase minerals, rocks or fossils, 

 will do well to send to Prof. W. O. Crosby, Boston 

 Society of Natural History, Boston, Mass., for a cata- 

 logue of specimens and collections. 



