314 FOUNDERS OF OCEANOGRAPHY 



carbon that may be present, and estimates have varied 

 from less than one to over ninety milligrammes per litre of 

 sea- water. 



The general result of the work initiated by Hensen and 

 carried out by the Kiel school of investigators has certainly 

 been to emphasize the importance of the plankton as supply- 

 ing the nutriment that is necessary for the existence of 

 other marine animals. The extreme view put forward by 

 some was that we could actually estimate from a few smaU 

 samples the total amount of food available in wide oceanic 

 areas, and therefore the number of fishes or other animals 

 that could be supported. 



Possibly as a reaction against the views of the Hensen 

 school, the physiologist Professor August Piitter of Bonn, 

 in a series of remarkable papers from 1907 to 1912, attempted 

 to prove that the plankton in the sea is utterly insufficient 

 to nourish the animals which are supposed to feed upon it, 

 and that not only simple and minute organisms but also 

 large highly organized animals with a well-developed 

 alimentary canal, such as Crustacea, MoUusca and even true 

 fishes, could and do obtain most of their nutriment from 

 the dissolved organic matter in the water. He holds (1) 

 that the mass of plankton in sea-water is much too small 

 in amount to meet the food requirements of the larger 

 animals, and (2) that an abundant source of food is present 

 in the form of the dissolved organic compounds in the water, 

 and that it is on these that the sea- animals are nourished. 

 This view was referred to, briefly, in the chapter on plankton ; 

 but, though very improbable, it deals with such important 

 fundamental matters that it must be discussed at greater 

 length here. 



According to Piitter, then, the living plankton is of 

 comparatively slight importance as a food material, and 

 many animals of the sea are nourished, somewhat like 

 endoparasites in the bodies of higher animals, by the 

 dissolved organic substances resulting from the decay and 



