ZOOLOGICAL SOCIKT^ lUI.LKTlN 



Very often the movement of 

 the jaws and eyes almost 

 ceases. 



In the puffer [Splieroidcs 

 mactilalus) at rest, the fins 

 are closely folded, and the 

 fleshy folds above and below 

 the eye, which have almost 

 the form of eyelids, cause the 

 eyes to appear closed, or 

 nearly so. In the respiration 

 of the fish there is practically 

 no movement of the jaws, 

 which are carried about half 

 open. The body shows a slight 

 breathing movement in unison 

 with the slow and almost im- 

 perceptible movements of the 

 tips of the gill covers. 



There seems to be little doubt that many of these 

 resting positions indicate sleep. 



DO FISHES HEAR? 



DURING recent years experiments have been 

 made which make it possible to answer this 

 question in the affirmative, for some kinds of fishes 

 at least. 



Fishes are well known to be sensitive to dis- 

 turbances of the water, but are usually not affected 

 by noi.ses made above the water except when it 

 amounts to a heavy concussion. 



It has been found that fishes, reported to ap- 

 proach their keeper at the ringing of a bell, will also 

 do .so without the bell being used, while the ringing 

 of the bell will not bring them if the keeper remains 

 out of sight. 



Sounds produced under water and scarcely dis- 

 tinguishable in the air may be heard distinctly by 

 placing the head under water, while sounds pro- 

 duced in the air are scarcely heard when the head is 

 immersed. 



According to Professor Parker of Harvard, who 

 made repeated experiments with a view to testing 

 the hearing powers of fishes, "the plain separating 

 air and water, is under ordinary circumstances, an 

 almost impenetrable one for most sounds whether 

 they are generated on one side or the other of it." 

 Experiments made in transmitting sounds under the 



YELLOW-UN GROUPKR. 



water have lead Professor Parker to state that there 

 are fishes which do hear. 



Bigelow's experiments with the goldfish lead him 

 to the conclusion that it possesses the sense of 

 hearing. 



Although fishes have no external ears, they possess 

 the internal organs of hearing in some form. There 

 can be little doubt that the sounds made under 

 water by many kinds of fishes are audil)le to others 

 of their own species. 



H.WE FISHES MEMORY? 



IX view of the well known facts that fishes can be 

 frightened and become wild, that their confidence 

 can be gained to the extent of making them tame so 

 that some of them will permit handling, that they 

 learn to come at certain times to certain places to be 

 fed, that habits learned in the Aquarium are some- 

 times resumed after the fish has been liberated for 

 months in a pond and then returned to the Aquarium, 

 and that some fishes which have been injured by the 

 hook, and escape, are afterward difficult to capture, 

 it is natural to conclude that they have some power 

 of memory. 



The seasonal movements of fishes, certain actions 

 in the Aquarium which resemble play, and the 

 sounds which they make, also indicate that they 

 remember in a measure what thev have done before. 



