PSMWiXZE vii 



obtained in most cases from the respective experiment stations or 

 from the Superintendent of Documents at Washington, either 

 gratis or at a nominal price. 



It is a pleasure to the authors to acknowledge their indebtedness 

 to Professor R. A. Harper, now of Columbia University. Whatever 

 value this book may have is due in large measure to the stimulus 

 that came through their years of association with him and to the 

 inspiration furnished by his discussions of the problems of botanical 

 teaching, and by his example as a teacher. Of the many others 

 to whom the authors are indebted for assistance, special mention 

 should be made of Dr. C. A. Fuller, now of Providence, Rhode Is- 

 ■land, whose valuable suggestions aided in the preparation of Chapter 

 II ; Professor E. T. Harper, of Geneseo, Illinois, upon whose col- 

 lection of photographs of the fleshy fungi we have freely drawn; 

 Mr. F. B. Moody of the Wisconsin State Conservation Commis- 

 sion, who furnished several of the photographs used in illustrating 

 Chapter XXII ; President V. E. McCaskill of the Superior State 

 Normal School, who has read and criticized several of the chapters ; 

 Professors L. R. Jones, G. W. Keitt, and A. G. Johnson, of the 

 Department of Plant Pathology of the University of Wisconsin, 

 for assistance especially in the preparation of Chapter XXIV ; 

 Professor Alban Stewart of the Florida College for Women ; and 

 to the various members of the Department of Botany of the Uni- 

 versity of Wisconsin, especially Professors J. B. Overton, R. H. 

 Denniston, E. T. Bartholomew, and G. M. Smith, Dr. W. N. Steil, 

 Dr. G. S. Bryan, and Mrs. P. M. Smith, for assistance and sug- 

 gestions in connection with all parts of the work. 



Madison, Wisconsin. 

 May, 1917. 



