ELISHA MITCHELL SCIENTIFIC SOCIETY. 27 



of the curators of some of the larger public aud semi-public 

 herbaria, of which the country hn'^ already an ample supply. 



The Gray herbarium at Cambridge, Mass., would alone be 

 sufficient for all necessary purposes. Besides this, there are at 

 the National Capital two large collections : one at the Depart- 

 ment of Agriculture, of which Dr. George Vasey is curator; 

 the other at the National Museum, in charge of Professor Lester 

 F. Ward. These herbaria are public property and may be con- 

 sulted in person by any student, or by letter addressed to the 

 respective curators. As the value of such collections depends 

 laigely upon their completeness, private collectors should take 

 pride in making them as complete as possible by depositing with 

 them all their more valuable typical specimens, and by collecting 

 further under the intelligent direction of the curators. 



But this kind of botany, though not to be despised, is not the 

 most valuable work that the local botanist may do. He may, 

 by observation aud experiment, seek to discover the useful aud 

 noxious properties of the plants more or less peculiar to his 

 locality; the environment most affected by particular species; the 

 means by which they accomplish the fertilization of their ovules 

 and the dispersion of their seeds; the effect of wet and dry, hot 

 aud cold seasons upon plant growth ; the parasites they harbor, 

 and many other interesting, useful and yet unsolved problems in 

 plant physiology and pathology. A single student of this sort 

 of botany may do more in a life-time to advance the cause of 

 human progress than can be accomplished by the united labors 

 of any number of herbariumists continued through all eternity. 



Activity of whatever kind whicli subserves no useful purpose 

 in regard to human welfare is a criminal abuse of the trust 

 Humanity has reposed in each one to whom she has given the 

 power of thinking and acting, that tliey might thereby smooth 

 her pathway and accelerate her progress toward perfection. 

 Viewed solely as a means of discij)lining the intellectual facul- 

 ties, botany is unequalled by any other of the natural or i)hysi- 

 cal sciences. 



