250 MARKKTAl'.LE BRITISH MARINE FISHES 



although small bivalves were sometimes found in the entire con- 

 dition. The throat teeth of the sole are pointed and slender, 

 and cannot serve for crushing shells as do those of the plaice. 

 Twenty-five per cent, of the stomachs contained echinoderms, 

 mostly sand-stars. Crustacea were only found in 1 1 per cent. 

 On the west coast of Ireland the order of importance of the 

 different kinds of food was found to be the same : worms were 

 most frequent, then sand-stars or other echinoderms, then mol- 

 luscs, then crustaceans, and lastly fish in a few cases. The 

 echinoderms were mostly brittle-stars or sand-stars, among the 

 molluscs were small specimens of the razor shell, the crustaceans 

 were usually small sand-hoppers or shrimps, the fish small sand- 

 eels. 



In the aquarium the sole will eat marine worms, shrimps, and 

 pieces of fish or molluscs such as queens (Pecten} or mussels : 

 but it prefers worms. When searching for food, whose presence it 

 recognises by the smell, it glides gently about over the sand tap- 

 ping with the lower side of its head in order to feel with the 

 sensitive filaments there. But it soon gets accustomed to expect 

 the food thrown into the tank, and often swims up from the 

 bottom to seize it, although it is not very expert in doing this. 

 Agitation of a handkerchief in front of the glass will cause the 

 soles to collect to the front in expectation of food. The sole is 

 one of the flat-fishes most addicted to burying themselves in the 

 sand or gravel, leaving only their eyes exposed. 



It is much more active by night than by day. This is proved 

 not only by the unanimous testimony of fishermen that more 

 soles are to be caught by trawling at night than by day, but by 

 observation in the aquarium. On a visit after dark the soles arc 

 always found to be out of the sand, moving with some activity 

 and searching for food, and when a light is directed upon them 

 they soon bury themselves. As the sole trusts chiefly to the 

 senses of smell and touch to find its prey, it can obtain food 

 without difficulty in the dark, and seems in the natural state to 

 use its eyes but little in hunting, a fact which is in agreement 

 with the small size and slight mobility of those organs. 



It is possible to capture soles by hook and line, but this 

 method appears nowhere to be employed by professional fisher- 

 men except at Scarborough. A few men at that port set ground 

 lines for soles in a little bay called ^Cloughton \Yyke north of 



