PREFACE VII 



my research. I am also greatly indebted to the National Ee- 

 search Council of Italy for a special grant for visiting some 

 European libraries, and to all friends and pteridologists, too 

 numerous to mention individually, who have sent me papers or 

 have helped me in many other ways. Furthermore I wish to ex- 

 press my sincere appreciation and gratitude to F. A. St fleu 

 of Utrecht, A. A. Bullock of Kew and E. Eoss of the British 

 Museum (Natural History) for advice on various problems of 

 nomenclature, and to my Assistants of the Istituto Botanico 

 « Hanbury » dell'TJniversita di Genova for the generous help I 

 have received on many occasions. 



Finally I wish to express my dearest thanks to my wife, 

 whose patient and constant assistance with typing and check- 

 ing cards, and in correcting proofs, has been extremely im- 

 portant for the completion of this work. 



EoDOLFO E. G. Pichi-Sermolli 



Genova, 25th April 1964* 



