PREFACE 



rilHE object of this book is to give a short account of the main 

 -*- results of modern quantitative marine biological investiga- 

 tions, and of the related results of hydrography and oceanography. 

 There is at present no adequate summary of these researches 

 in English ; and although several German accounts have been 

 published these do not seem to be very well known in this country. 

 Already a great number of memoirs have been written, but 

 the publications in which these have appeared are not very 

 accessible, even in the ordinary biological libraries. Much of the 

 work, especially that relating to the methods of plankton research, 

 and to the hydrodynamical investigation of ocean currents, is very 

 technical and can hardly be summarised in a book of this character. 

 So I have referred to the most important memoirs, and from these, 

 and the further references which they contain, the reader will be 

 able to tap the original sources of information. Part I. of the 

 book is rather elementary in treatment, the object being to supply 

 an account of those facts of oceanography which are not likely to 

 be familiar ta the reader who is not specially interested in marine 

 biological investigation. Part II. deals with the methods and 

 results of quantitative marine biological research ; and Part III. 

 with the general conditions of life in .the sea. 



It is characteristic of a really great idea in science that it 

 should stimulate further discovery by the suggestion of new lines 



