ON THE PERCEPTIONS AND MODES OF 

 FEEDING OF FISHES. 



W. BATESON, M.A. 



St John's College. 



In the course of observations made at Plymouth and elsewhere 

 it appeared that the majority of Fishes are diurnal in their habits 

 and seek their food by sight, but that a minority are almost 

 entirely nocturnal and hunt by scent. To the latter class belong 

 Protopterus, Skates and Rays, the Rough Dogfish, Sterlet, Eel, 

 Conger, Rocklings, Loaches, Soles, &c. These creatures remain 

 buried or hidden by day but career about at night in search of 

 food, returning to their own places at dawn. If while they are 

 thus lying hid, food or even the juice of food-substances is put 

 into the water, they come out after an interval and search vaguely, 

 without regard to the direction whence the scent proceeds. Sonje 

 of the animals (Rocklings, Sterlet) have special tactile organs in 

 the shape of barbels or filamentous fins with which they investi- 

 gate their neighbourhood, while others (Conger and Eels) feel 

 about with their noses. None of the fishes which hunt by scent 

 seem able to recognise food by the sense of sight, even though it 

 be hanging freely before their eyes. 



The mode of feeding of the Sole is peculiar. When searching 

 for food its skin is more or less covered with sand, which renders 

 it inconspicuous when moving on the bottom. This sand adheres 

 to mucus which is probably exuded when the smell of food is 

 perceived. The Sole seeks its food exclusively on the bottom, 

 creeping about and feeling for it with the lower side of its face. 

 If a worm is lowered by a thread until it actually touches the 



