A GUIDE TO THE STUDY 



OF 



LICHENS 



ALBERT SCHNEIDER, M. D., Ph.D. 



Professor of Botany, Materia Medica and Pharmacognosy, 

 California College of Pharmacy, San Francisco 



With frontispiece in color 



and 



Twenty plates 



SECOND EDITION 



BOSTON 



KNIGHT AND MILLET 



1904 



