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Finland. Investigations of the composition of the year-classes of Coregonus 

 alhnla have been carried on in the lakes Keitele, Nilakka and Pielavesi. 



Investigations of the salmon have also been carried on in the Ulea river 

 at the Bothnian Bay and in the Kymmene river at the Finnish Bay and have during 

 the summer 1922 been extended to the Kemi river in the northern part of Finland. 



Holland. An intensive study of the plankton of our brackish-water has 

 been undertaken; a report by Dr. Redeke, Miss G. de Lint and Dr. van Goor: 

 "Prodromus eener flora en fauna van het Nederlandsche zoet- en brakwaterplankton" 

 including the plankton of the estuaries of the Rhine was printed. 



Extensive investigations have been made on the life history of young salmon 

 and trout in the brooks of the most southern province of the Netherlands (Limburg), 

 including age-determinations and food-supply. 



Sweden. No researches on Coregonus, but salmon work continued from 

 previous years. 



France. Les recherches indiquées ont été effectuées par M. le professeur 

 Roule qui a remis au Comité Limnologique deux notes sur ces questions. 



m. Professor Joubin's recommendations in regard to Molluscs. 



England. 8 — 9) A report is being completed by Dr. J. H. Orton of the Ply- 

 mouth Laboratory on the results of the investigations carried out by him during 

 the past year on the oyster mortality in England. 



These investigations into the cause of the abnormal mortality amongst 

 oysters have now been handed over to the Ministry. Samples of sound and "hockley" 

 (sick) oysters have been forwarded to the Laboratory from Whitstable weekly 

 since May 4th. The leucocytes of the blood are examined to see if any change takes 

 place with regard to the proportion of the different kinds, or in their structure, 

 inclusions etc.; bacteriological examinations will also be carried out. 



Work has been carried out also at the Millport Marine Laboratory on the 

 effect of the oil found in considerable quantity, on or near the oyster beds of the 

 Thames Estuary. 



10) A preliminary survey of the South Wales oyster beds has been carried 

 out at the request of the South Wales Sea Fisheries Committee. The object of the 

 examination was to determine the present condition of the beds, and to formulate 

 recommendations for the re-stocking them, as they have become much depleted. 



