viii PREFACE 



Part II is devoted to the Rust Fungi which, Hke the Hymeno- 

 mycetes, have been considered from the point of view of the produc- 

 tion and liberation of their spores. I have shown that the phenomena 

 accompanying the development and discharge of basidiospores are 

 exactly alike in the Uredineae and Hymenomycetes, thus strengthen- 

 ing the view that these two great groups are closely related. I have 

 also described in detail, for the first time, my observations on the 

 violent discharge of the basidiospores and aecidiospores of Puccinia 

 graminis. 



The volume contains two hundred and twenty-seven illustra- 

 tions, including one hundred and fourteen drawings and one hundred 

 and thirteen photographs. Fifteen of the drawings and fifteen of 

 the photographs have been borrowed from other authors. The 

 other ninety-nine drawings were executed by my own hand. For 

 copying the drawings reproduced in Figs. 183, 188, and 191, my 

 thanks are due to Dr. Nellie Carter. The source of each borrowed 

 illustration is duly acknowledged in the text. 



Of the ninety-eight photographs here published for the first time, 

 sixty-six were made under my direction ; and the others were very 

 kindly contributed by friends and correspondents : six by A. E. 

 Peck ; four each by W. S. Odell and J. E. Titley ; three by Miss 

 E. M. Wakefield ; two each by A. E. Field and W. F. Hanna, P. 

 Grafton, J. P. Hillhouse, and Miss Irene Mounce ; and one each by 

 Mrs. J. S. Bayliss Elliott, H. M. Fitzpatrick, H. T. Gussow, Somerville 

 Hastings, the late W. Hillhouse, C. D. Learn, and H. R. Wakefield. 



To numerous correspondents in both Europe and North America 

 I am indebted for assistance rendered me by sending specimens, 

 photographs of fungi, reprints of papers, and books, and by supplying 

 information in response to various inquiries. In this connection my 

 thanks are due especially to Miss E. M. Wakefield, M.A., of the 

 Royal Herbarium, Kew, J. Ramsbottom, M.A., of the Natural 

 History Museum, South Kensington, and Dr Howard A. Kelly of 

 Baltimore. In the final revision of the proofs, W. B. Grove, M.A., 

 to whom this volume is dedicated, has once more given me the benefit 

 of his wide mycological knowledge and experience. 



A. H. REGINALD BULLER. 

 Winnipeg, August 19, 1924. 



