INTRODUCTION 



IN this book an endeavour has been made to survey 

 systematically the ocean's teeming populace in a 

 manner acceptable to the general reader. I have 

 attempted to summarise all the principal groups of maritime 

 life, pointing out the more interesting members and in 

 particular showing how each group contains individuals 

 attuned to almost every conceivable environment provided 

 by the open waters or the coastal areas constituting their 

 boundaries. 



How vast is the ocean and how pregnant it is with 

 as yet unexplored possibilities, we are only to-day beginning 

 to fully realise. In the days of early Greece the ocean 

 was regarded as a river flowing round the then known 

 world. Nowadays the ocean is mapped with some 

 accuracy, its waters and the countless waterways which 

 serve to feed it covering more than two-thirds of the 

 earth's surface. The portion immediately washing the 

 great land masses rests upon what is known as the Con- 

 tinental Shelf and is comparatively shallow. This, 

 however, quickly descends to considerable depths and the 

 deeps proper — many of which doubtless yet remain to 

 be discovered — plunge vertically into Stygian blackness 

 for from two to more than four miles. The vastness 

 of this body of water reduced to figures is scarcely less 

 intimidating than the statistics inseparable from the study 



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