SEA-FISHERIES LABORATORY. 71 



making use of surplus production seem to us to be the one 

 which, must give the keynote to the scientific research of the 

 near future and reconcile the administrators to investigations 

 which, no doubt, seem abstruse and pedantic in the extreme. 



Further Work on the Plaice. 



Some other researches, which are not of a routine nature, 

 have been made, or are in progress, but are not published here. 

 A series of drift-bottle experiments and corresponding fish- 

 marking experiments were made by W. C. Smith in the study 

 of the Solway spawning grounds. These tend to show that the 

 area of the Irish Sea, north from Isle of Man and St. Bees' Head, 

 is a self-contained one, so far as the plaice is concerned. Along 

 with this an account of the Cumberland sea-fisheries in 1919 

 has been prepared. Collections of small plaice were made on 

 the Manx and Cheshire foreshores by W. Birtwistle and W. C. 

 Smith, and the feeding of these has been studied by A. Scott, 

 who has also identified the food organisms found in a large 

 number of larval and post-larval plaice spawned and reared 

 at Port Erin : the results of this latter investigation are being- 

 published elsewhere. Plankton is being collected from the 

 spawning and rearing ponds at Port Erin, and this is being- 

 described by A. Scott, for comparison with collections being- 

 made simultaneously in the adjacent sea. It is hoped that 

 some useful information as to the nutrition of larval plaice 

 may thus be obtained. Some much-needed experimental work 

 on conditions of metabolism of developing plaice eggs has also 

 been commenced by Professor Dakin, but this research is still 

 in the tentative stages. Finally, a study of morphological 

 variability in plaice is also being made. 



The Biometric Investigation of the Herring. 



In 1913 the Ministry of Agriculture and Fisheries request ed 

 this Laboratory to take part in a general scheme of invest iga.t ion 

 into the various races of herring which were assumed to inhabit 



