•280 THE ZOOLOGIST. 



Tristram, of Durham, saw Mr. Slack's bird, and said no doubt it is a 

 hen Eustic Bunting. Very few specimens of this species have been 

 seen in England, and its name does not appear in Mr. Hancock's 

 Catalogue of the Birds of Northumberland and Durham.'" 



Mr. J. Travis Jenkins, writing in the July issue of ' Knowledge and 

 Scientific News ' on the subject of the migration of flat-fish, states : — 



" The majority of scientific experts agree that round fish, i. e. fish 

 of the Herring and.. Cod type, perform migratory movements of con- 

 siderable magnitude, but as regards flat-fish, i. e. Plaice, Soles, and 

 Flounders, the consensus of opinion is by no means so unanimous. 



" The International Committee for Investigation of the Seas, which 

 has quite recently been established, has taken up, among other pro- 

 blems, the question of the migration of members of the flat-fish family, 

 or Pleuronectidce. This international committee consists of scientific 

 experts nominated by the Governments of England, Norway, Sweden, 

 Germany, and Holland, and is subsidized by grants from the respective 

 Governments. Batches of marked Pleuronectids, chiefly Plaice, have 

 been marked from time to time, and then liberated at various points in 

 the North Sea. The mark used consists of a silver wire, which is 

 threaded through the body of the fish. To this wire are attached on 

 the under side a bone button, and on the upper side a numbered brass 

 label. Each fish is carefully measured and labelled, the whole opera- 

 tion from the time the fish is removed from the tank to the time it is 

 replaced taking less than one minute. It is hoped that by these experi- 

 ments the amount and nature of the migration of flat-fish will be 

 determined, and attempts will be made to show the influence of the 

 environment on migration. The intensity of fishing in any given area 

 can be determined by the proportion of fish recaptured to the total 

 number of marked fish returned to the sea. Since each marked fish is 

 carefully measured both when it is returned to the sea and when re- 

 captured, the rate of growth can also be determined. Plaice seem to 

 withstand the marking operation wonderfully well, but Soles are far 

 more difficult to deal with successfully. No doubt other results will be 

 arrived at, notably the efficacy of closed grounds in maintaining a 

 reserve of fish, and the effect of the density of fish population on the 

 rate of growth." 



