THE SENSE-OllGANS AND PEUCEPTION OF FISHES. 251 



they were lying at the top of the water^ as the mullet were observed 

 to do in the aquarium. 



Hearing. — Several attempts were made to determine the class of 

 sounds which fishes can hear. During the month of November some 

 blasting operations were carried out on the premises of the Asso- 

 ciation, and particular notice was taken of the behaviour of the fish. 

 The pouting scattered for a moment in all directions when the report 

 came, but were quiet directly afterwards. The soles, plaice and 

 turbot buried themselves. The conger drew back a few inches, as 

 is their habit also when a light is turned on them at night, and gene- 

 rally on being disturbed. None of the other fishes were seen to 

 take any notice of the report. 



As mentioned in this Journal (N. S., i, 2, p. 217), satisfactory evi- 

 dence was obtained that the creaking sound made by smearing a wet 

 finger on the glass window of the tank was heard by a Lamellibranch 

 (Anoviia) . For some time I was of opinion that the same sound was 

 heard by some fishes (pollack, &c.) which at once come to the spot and 

 follow the finger. Mr. Wells, of the Brighton Aquarium, told me that 

 his own observations led him also to believe this, especially in the case 

 of bream, which come to the front in a body when this sound is made. 

 Nevertheless, on further trials I saw no reason to suppose that the 

 fish were not merely following the finger by sight, and I never saw 

 them (pollack) attracted when the sound was made behind a screen 

 of silk or weeds sunk in the water, and such a screen would scarcely 

 interfere with the transmission of the sound. The movements of the 

 bream at Brighton did not, however, resemble those of fishes trying 

 to catch a particular piece of food, but were distinctly suggestive of 

 general expectation. Seeing that the case of the Anomia proves 

 that sensible vibrations are thus actually set up in the water, it may 

 be that they hear them. The sound made by pebbles rattling inside 

 an opaque glass tube does not attract or alarm pollack ; neither are 

 they affected by the sharp sound made by letting a hanging stone 

 tap against an opaque glass plate standing vertically in the water. 

 If they see the stones in either of these cases they follow them, but 

 if the glass is opaque they do not. When the wall of the tank is 

 struck with a heavy stick they behave as described in the case of 

 blasting. As might be expected, none of the fishes were seen to 

 take notice of sounds made in the air. Various loud noises were 

 tried, but soles, for instance, when exposed did not bury themselves 

 as they do when the side of the tank is struck. Probably, therefore, 

 they did not hear the noises. The stories, for example, quoted in 

 Day's British Fishes, p. xxxviii, of fishes coming to be fed when a bell 

 was rung, can scarcely be taken to prove that the sound of the bell 

 was heard by them, unless it be clearly proven that the person about 



