434 M. V. LEBOUR. 
PAGE 
Gadus morrhua : : : ‘ 3 : : ; : : . 454 
Gadus merlangus . é : : : : : : ; : : . 454 
Gadus luscus . 5 : : : : : : ; : ; : . 455 
Gadus pollachius . 3 ; 5 ; : ; : . ; 2 =) 455 
Gadus minutus 5 ; : ; : 3 : : : ; : . 455 
Onos mustela. : : : : : ‘ : : : ; : . 456 
Ammodytes tobianus —. : ; : é : : ; : . 456 
Ammodytes lanceolatus . ; : : : ; : . . 456 
Gasterosteus spinachia . ; ; . : : : : . 456 
Syngnathusacus . ; : : 5 ; ; : : F : . 456 
Syngnathus rostellatus . ; ; : : : L : : . 2 Api 
Nerophis lumbriciformis . ‘ ; é : . 3 : : : a iz) 
Clupea harengus. , : : : i : : : : ton 
Clupea sprattus . 3 5 : : : : ; . ; : . 459 
Literature. ‘ : ; : 2 , : i : : . 460 
Table of Post-larval fish from tow-nets —. : : 5 F ‘ : . 461 
ALTHOUGH much investigation has been made on the food of adult fish 
the information as to the food of the very young is scattered and frag- 
mentary. It is the purpose of this paper to report on the food of a 
number of post-larval fish which have been examined fresh from the 
tow-nettings through the year 1917 from Plymouth Sound within the 
Breakwater and outside as far as the region of the Panther and Knap 
Buoys (about 24 miles from the shore) and occasionally from Cawsand 
Bay. The food of a number of preserved post-larval fish has also been 
investigated which were taken in the Young Fish Trawl in 1914 and 
reported on by Dr. Allen (1917). These latter were mostly examined as 
mounted and cleared preparations, the food usually being plainly seen. 
Others from this lot were examined by dissecting out the alimentary 
canal—a method not so satisfactory for preserved material although 
answering very well for the fresh fish which were all examined by this 
latter method. 
A systematic examination of post-larval fish from tow-nettings was 
made by A. Scott (1906), who used the above methods, but the number 
examined was not large. Herdman (1893-1898) had also previously 
noted the contents of the alimentary canal in several young fish, chiefly 
those beyond the post-larval stages. Petersen (1894, 1917) also notes 
the food of young fish, especially Plewronectide. Other records have 
chiefly to do with the food of artificially reared fish, when the food picked 
out by the post-larval fish from plankton given to them is noted. 
In all these records it is found that the Copepoda form the chief food 
of nearly all larval and post-larval fish with other Entomostraca and 
Mollusk larve. It now seems to be a well established fact that the 
majority of young fish eat the small animals from the plankton more 
than the diatoms and other unicellular organisms, except in cases of some 
of the very young fish which have been found to eat diatoms before 
taking to animal food (Kyle (1898) found Dab from 10 to 16mm. with 
