X BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



sense "dead work." Yet in another it is vital. It is in 

 itself of only temporary value. It perishes with the using. 

 The user may soon get beyond the need of a crutch. 



The only justification for such work is its usefulness to 

 amateurs, who may by its help put bryologists in posses- 

 sion of facts regarding the distribution, variation, and re- 

 lationships of our moss flora which could not be gained 

 without their aid. These keys are published, therefore, 

 purely as an encouragement to the study of our mosses, 

 which with the Hepaticse are more neglected than any 

 other group of which we have accessible descriptions. 



An earnest student equipped with patience, some skill in 

 dissection, a compound microscope, and the Manual, ought 

 to be able with the assistance of these keys to determine 

 the names of most of the mosses which he can collect. 

 Those which remain uncertain he can refer to those who 

 possess the illustrations and exsiccati which are often in- 

 dispensable for identification. 



Charles R. Barnes. 

 University of Wisconsin, 



December 15, 1896. 



