viii PREFACE 



Herbarium of the Royal Botanic Gardens at Kew and in the 

 Botanical Department of the University of Birmingham. It is 

 with much pleasure that I here acknowledge the courtesy of the 

 authorities at Kew and Birmingham for the facilities accorded me. 



Of the one hundred and fifty-seven illustrations, all but twelve 

 are here published for the first time. The source of each borrowed 

 illustration is duly acknowledged in the text. Of the seventy-seven 

 drawings, sixty-nine were executed by my own hand. Of the 

 eighty photographs, thirty-one were made under my direction ; and 

 the others, with the exception of four taken from previous publica- 

 tions, were very kindly contributed by friends and correspondents : 

 fourteen by A. E. Peck ; eleven by Somerville Hastings ; three 

 each by J. E. Titley, J. H. Faull, and C. J. Humphrey ; two each 

 by Miss E. M. Wakefield, C. W. Lowe, B. Leeper, and W. S. Odell ; 

 and one each by G. G. Hedgcock, R. Hancock, and W. B. Grove, 

 the last having been taken by the late J. Edmonds. 



I desire to thank nry numerous correspondents in both Europe 

 and North America for assisting me by sending specimens of fungi 

 and reprints of papers, and by supplying information of various 

 kinds in response to my enquiries. Dr. Guy Barlow has been good 

 enough to help me with the sections relating to the revised formula 

 for Stokes' Law. In the final revision of the proofs, my friend, 

 W. B. Grove, M.A., has again given me the benefit of his wide 

 mycological knowledge and experience. 



Finally, I wish to express my indebtedness to the Birmingham 

 Natural History and Philosophical Society for a grant of 25 toward 

 the cost of making the blocks for the illustrations of this volume, 

 and to the Canadian National Council for Scientific and Industrial 

 Research for a grant of $1,000 toward the expense of producing 

 this volume and the two which are to follow it. 



A. H. REGINALD BULLER. 



WINNIPEG, October 22, 1922. 



