At the request of the Bureau of the International Council for the study of the sea, and 

 with the assistance of the members of the Committee, I submit a provisional summary of the 

 work of Committee B, so far as this concerns the natural history of the plaice {Pleiironedes platessa). 



In preparing this report I have endeavoured to restrict myself as much as possible to an 

 objective summary of the facts placed at the disposal of the Committee. In places where I 

 have departed from this attitude aud expressed any personal opinions, it should be understood 

 that such opinions have been advanced for suggestive purposes alone and not in any way to 

 pre-judge the conclusions which the Committee may ultimately adopt in regard to the matters 

 under discussion. 



The primary object of the Committee is to make so thorough and profound an investigation 

 of the natural history of the plaice and other trawl-caught fishes that it may be possible to 

 apply such knowledge for the increase of the food supply dependent ïipon the trawling industry. 

 The scope of the Committee's work is therefore sufficiently great and the responsibility no less 

 serious. 



I trust that the present report upon the natural history of the plaice may be taken as 

 evidence that the Committee have realised the magnitude of their task, and that they have 

 confidence, with a continuance of the present means at their disposal, in their ability to bring 

 it to a successful conclusion. 



In the collation and revision of tlie data dealt with in the present report I have been 

 greatly assisted by my colleagues at the Lowestoft Laboratory, especially by Mr. J. 0. Borley 

 and Mr. E.A.Todd. 



A. Experiments with marked plaice 



1. Introduction 



Up to the end of December, 1903, successful experiments with marked plaice had been 

 carried out by the investigators of Sweden, Denmark, Germany, Holland and England. Parti- 

 culars have been received concerning the liberation of 6,239 marked plaice, of which 890 had 

 been caught again by the fishermen up to June 30, 1904. The details for eacli country are 

 given in the acompanying table. 



