60 SUPPLEMENT TO THE BOOK OF THE BLACK BASS. 



further inward from the surface. Thus a new method for con- 

 ducting the sound waves is necessitated, and the following struc- 

 tures become developed, etc." — (Wiedersheim.) 



"Many Teleostei [true fishes] have fontanelles in the roof of 

 the skidl, closed by skin or very thin bone only at the place 

 where the auditory organ approaches the surface, by which 

 means sonorous undulations must be conducted with greater ease 

 to the ear." — (Giinther.) 



"In many Teleostei a most remarkable relation obtains be- 

 tween the organ of hearing and the air-bladder. In the most 

 simple form, this connection is established in Percoids and the 

 allied families, in which the two anterior horns of the air-bladder 

 are attached to fontanelles of the occipital region of the skull." — 

 (Giinther.) 



The air-bladder, in such cases, may, in a manner, per- 

 form the functions of a tympanum. 



I append a few sensible remarks from an article by W. 

 N. Lockington, in " Pacific Life :" 



" It appears to be not unlikely that fish take no notice of sounds 

 produced in the air, but it is not so easy, unless we can argue the 

 matter from a fish's point of view, to prove they do not hear 

 those sounds. Take the sense of sight as an illustration of that 

 of hearing. I have often amused myself by making believe to 

 strike a monkey that lived in a cage with a glass front. Accus- 

 tomed to such demonstrations, the monkey simply took no notice. 

 His bright eyes never even winked. Arguing, as was argued in 

 the fish case, I might say monkeys can not see. 



"All fishes have an organ of hearing ; not a rudimentary or- 

 gan, but one complete in its kind, and differing from ours only 

 iu its degree of development ; differing, in fact, much in the 

 same way that the brain, the heart, the intestines, the skeleton, 



