Dakin and Latarche— The Plankton of Lough Neagh. 21 



where biological research is being pursued with so much energy at present. 

 If it had not been for Sir John Murray and the Messrs. "West, the British 

 Islands would have been left hopelessly behind in investigations of this 

 kind. 



It is quite impossible for us to treat the historical side of fresh-water 

 plankton research, for it has expanded to an enormous extent during the last 

 twenty years. From the pioneer work represented by that fine monograph, 

 " Le Leman " of Forel, it has extended until numerous specialists have taken 

 up and treated not the plankton in general, but finally perhaps one particular 

 genus alone. 



It is only fitting that mention should be made here of the death of Forel, 

 which occurred as this paper was nearing completion. He passed away on 

 August 7 at the age of seventy-one years. Professor F. A. Forel was born at 

 Morges on the shores of Lake Geneva, the lake to which he devoted his life in 

 study. From 1868 onwards numerous papers have been given to the world 

 dealing with the hydrobiology and hydrography of its waters. His great 

 monograph on " Le Leman " which appeared between 1892 and 1904, is a 

 foundation of scientific limnological research, and is remarkable for the wide 

 range of knowledge, extending over very many sciences, possessed and turned 

 to good account by the author. 



It is perhaps in connexion with the theories of Seiches that Forel will be 

 best remembered. Unfortunately we have not been able to treat at all the 

 interesting subject of oscillatory movements in the waters of Lough Neagh. 

 Little attention has, however, been paid to this subject; and Forel's contri- 

 butions are known almost only to the specialists, and in this country to those 

 keen workers on the Scottish lochs. There, Wedderburn and Murray have 

 extended the theories of Forel to temperature oscillations. 



Forel's life was devoted to science ; and he leaves behind a lasting record 

 of knowledge wrung from nature's hidden book. 



The lakes of the Arctic Eegions have been investigated by Ekman, 

 Wesenberg Lund, Scourfield, Penard, and others. The North Temperate lakes 

 have been treated in enormous detail, particularly the Baltic Lakes, for 

 which there is a prodigious amount of literature. Amongst workers there 

 may be mentioned Bachmann, Wesenberg Lund, West, Murray, Ostenfeld, 

 Huitfeldtkaas, Ekman, Lemmerman, Lilljeborg, Zacharias, Apstein, and 

 Seligo. 



The Alpine Lakes have been investigated in very considerable detail. In 

 America, we may note the work of Birge on Lake Mendota, Eeighard on 

 St. Clair, and Kofoid on the Illinois Eiver. The lakes in Asia and the Tropics 

 have also been investigated. The seasonal zooplankton of Irish lakes and 



[D2] 



