NATURE ADRIFT 



vessel; manv have several. Their structure and equipment vary according to 

 the work they are intended to do and the areas in which they do it. The 

 Arctic-going ships from Icelandic, Norwegian, Russian, English, Scottish, 

 German and Danish laboratories, for example (see Plate II), have to operate 

 in different conditions from those confmed to the tropics. In addition, 

 many naval ships are doing special survey work and there are the weather 

 ships keeping a watchful eye on weather conditions from their oceanic 

 stations. Almost all of these, big or small, collect plankton for one purpose or 

 another. Small wonder then, that all that is known about plankton could fdl 

 a full-sized library and that this book is just a fleeting ghmpse. 



The methods of catching plankton will naturally vary according to the 

 kind of plankton being investigated, the purpose for which the information 

 is required and the working conditions. In Chapter 2, some of the methods are 

 briefly surveyed, begirming with a simple strainer that the beginner can 

 himself use. The next logical step is to look at what is caught and Chapters 3 

 to 7 cover some of the range of types. In the next chapters we discuss these 

 creatures in their environment, their dependence on each other and their 

 importance in the economy of the sea. This leads to the closing chapters in 

 which something of their more subtle physiology and behaviour is described, 

 ending with a discussion of what we can do for our own good with this 

 immense larder of the sea. 



It is hoped that the serious student will get some benefit from this book, 

 though it is not written primarily for him, and there are, therefore, in most 

 of the chapters details that should make his way clearer but which can be 

 ignored by the general reader to the degree he chooses. 



