viii PREFACE 



in the text, including one hundred and thirty-four drawings and 

 ninety-seven photographs. Forty of the drawings have been 

 borrowed from other authors. The other drawings were executed 

 by my own hand or in conjunction with Miss Ruth Macrae. Of the 

 ninety-seven photographs fifty-six were made under my direction, 

 ten have been borrowed from other authors, and the rest were 

 kindly contributed by friends and correspondents : one each by 

 S. F. Ashby. Jessie S. Bayliss Elliott, W. S. Odell, and H. H. 

 Thornbury, two by F. Dickson and W. R. Fisher, two by Somerville 

 Hastings, three each by B. 0. Dodge, G. L. Fawcett, and W. H. 

 Long, five by A. E. Peck, and nine by the Photographic Division 

 of the Geological Survey of Canada. The source of each borrowed 

 illustration is acknowledged in the text. 



For the session 1933-1934 I was granted leave of absence from 

 the University of Manitoba, and this period has been spent at the 

 Herbarium of the Royal Botanic Gardens, Kew, in completing for 

 the press the MS. and illustrations of Volumes V and VI of these 

 Researches. For the facilities placed at my disposal for carrying out 

 this work I here desire to express to Sir Arthur Hill, Director of 

 Kew Gardens, and Mr. A. D. Cotton, Keeper of the Herbarium, 

 my hearty appreciation. 



My best thanks are due once more to the Canadian National 

 Research Council for grants in aid of the work. These grants 

 have enabled me to employ in succession two research assistants, 

 Miss Ruth Macrae, M.Sc. (McGill), and Miss Eleanor S. Dowding, 

 Ph.D. (Manitoba). The investigations on the gemmifers of Omphalia 

 flavida and on the heliotropism of the asci of Ascobolus magnificus 

 were carried out in conjunction with Miss Macrae, and certain 

 investigations upon the life-history and structure of Pilobolus in 

 conjunction wdth Dr. Dowding. I here desire to express my 

 indebtedness to these two ladies for their valuable services. Once 

 again Mr. W. B. Grove, M.A., has been kind enough to give me the 

 benefit of his assistance in reading the proofs. 



A. H. REGINALD BULLER. 



Kew, August 19, 1934. 



