xvi INTRODUCTION 



there will be opportunity to test all the variations which 

 organisms are ever venturing. It may be, indeed, that the 

 stimulating character of the littoral conditions has been in 

 itself, through the ages, provocative of those new departures 

 which form the raw materials of evolution. 



In any case the result has been multitudinous adapta- 

 tion. What variety of armour and of weapons, what 

 arrangements for securing the food which tends to slip past, 

 what diversity in breathing, how many different ways of 

 holding on and withstanding shock ! The book is a 

 treasury for the student of fitnesses. 



And besides those modes of " struggle " which secure 

 self-preservation in the widest sense, there are those which 

 secure the welfare of the offspring. Of " love " as of 

 " hunger " the shore affords many a fine illustration, and 

 here again the authors' work shows true perspective. 



Whether the earliest living creatures tenanted the shore 

 or the open sea, remains uncertain, but there can be no 

 doubt that most of the great stocks of animals have passed 

 through the discipline of the littoral life, and this is perhaps 

 the crowning interest — to try to trace the organic grip 

 that such influences as the tides have taken of the constitu- 

 tion of the great races — how even in man himself there are 

 as it were reminiscences of the school of the shore. 



The principles of biology can be studied in many 

 different ways. There are anatomical, physiological, syste- 

 matic, and other approaches — all with their merits. But this 

 book opens up another way — the study of a haunt and its 

 inhabitants, and the authors have been successful in 

 showing that this way is one that rewards. 



