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METHODS OF PLANKTON RESEARCH. 

 By W. J. Dakin, M.Sc. 



1851 Exhibition Scholar, University of Livetyool 



Introduction. 



During the last few years there has been a great 

 development in the study of those organisms which are 

 found floating in the waters of seas and lakes, and which, 

 though having in many cases the power of swimming, are 

 practically as much at the mercy of the winds and 

 currents as inanimate floating objects. Such organisms 

 are denoted by the term "Plankton," and, as their full 

 importance in the metabolism of the ocean has become 

 appreciated, so has this branch of zoology and botany, 

 which may be termed Planktonology, advanced from 

 qualitative to quantitative investigation. The work has 

 been carried on by both botanists and zoologists, but owes 

 its growth mainly to the latter, and in great part to the 

 German School, from the time of Johannes Mtiller 

 onwards to the present quantitative scientific study of the 

 Plankton which originated through the outstanding and 

 fundamental work of Victor Hensen, Professor of 

 Physiology in the University of Kiel. Hensen's work (1) 

 appeared in 1887, but as far back as 1867 he was interested 

 in the investigation of the sea in the interests of Fishery 

 questions, and held the view that an attempt to estimate 

 the productiveness of the sea would be an important step, 

 both scientifically and economically. Finally, whilst 

 working at the question of coast fisheries he attempted to 

 determine the number of fish in a defined region by 

 counting and estimating the number of floating fish eggs. 

 This led to the idea that it was both possible and necessary 



