STOCKHOLM, 1899. 107 



B. 



THE BIOLOGICAL WORK. 



(a) Determination of the topographical and bathymetrical distribution 

 of eggs and larva? of marine economic fishes ; for example, by quanti- 

 tative methods, such as those of Henseu, and with special reference 

 to the most important species, such as plaice, cod and haddock, herring, 

 etc. (See Appendix I.) 



(b) Continued investigation of the life-history and conditions of life 

 of young fishes of economic species in their post-larval stages and till 

 they reach maturity, with special reference to their local distribution. 



(c) Systematic observation of mature marketable fishes with refeiecce 

 to their local varieties and migrations, their conditions of life, nourish- 

 ment (as, for instance, by investigation of the contents of the stomach), 

 and natural enemies : also observations on the occurrence and nature 

 of fish food at the bottom, the surface and intermediate waters down to 

 depths of at least 600 metres. (See Appendix I.) 



(d) Determination of periodic variations in the occurrence, abundance, 

 and average size of economic fishes, and the causes of the same. 



(ft) Experimental fishings 07i the known fishing grounds during the 

 time of the fishery, as well as outside these areas and seasons. 



(b) Preparation of uniform statistics of the experimental catches, 

 with particulars of the number, species, size, weight, and condition 

 of the fish ; for example, as done on board the Garland by the Scottish 

 Fishery Board. 



(c) The uniform use of appropriate apparatus for the experimental 

 capture of the different species and sizes of fish. 



(d) The experimental marking and liberation of fish, for instance of 

 plaice, on as large a scale as possible and over extensive areas ; for 

 example, as carried out by Dr. C. G. Joh. Petersen and Dr. T. W. Fulton 

 (Eeports of the Danish Biological Station and the Fishery Board for 

 Scotland), and others. (See Appendix IV.) 



III. 

 (a) It is desirable to collect uniform statistics of the number, weight, 

 and value of the fish landed, of the means of capture, and of the persons 

 engaged in the industry ; for example, as in the General Reports of the 

 Scottish Fishery Board. 



