PREFACE vii 



as far as possible, takes no previous scientific training 

 for granted. The headings of the various chapters 

 sufficiently explain the general plan. With a single 

 exception, they have been written by Fellows of the 

 Society ; to the exception — Mrs. Dr. A. Weber vanBosse, 

 the wife of an Honorary Fellow, and herself distin- 

 guished for researches on Algae — the Society desires to 

 express its special indebtedness. To those who have 

 allowed the use of existing illustrations (notably to 

 Sir John Murray, who placed the blocks of the Reports 

 of H.M.S. Challenger at our disposal ; and to Mr. S. 

 Henshaw, Curator of the Museum of Comparative 

 Zoology at Cambridge, Mass., who allowed the use of 

 blocks from "Three Cruises of the Blake"), as also 

 to numerous manufacturers who have freely supplied 

 valuable information, the Society also renders its 

 thanks. 



The first edition of such a work as this is necessarily 

 of a tentative nature, and the Editor will gratefully 

 receive corrections and suggestions of all kinds for a 

 future issue. 



G. HERBERT FOWLER. 



Aspley Guise, 



Bedfordshire, 



April, 1912. 



