270 How to obtain it. 
the stomach and the air bladder, so that on inserting a tube and 
inflating the stomach, the air passes on and distends the air 
bladder also, and, what is more remarkable still, the posterior end 
of the bladder is found to narrow into a tube, which ends in an 
external aperture near the anal fin. So that the ear of the herring 
may be said to be connected with an external aperture. Many 
other fishes have the connection between the air bladder and the 
organs of hearing ; but the external aperture connecting with the 
air bladder seems to be absent, except in the herring. 
It has been suggested that the air bladder may act as a drum, 
and that sounds may be transmitted from it to the internal ear. 
Be this as it may, the question is one of great interest, and is well 
worthy of investigation. It is quite likely that many fishes which 
have not yet been thoroughly examined may be found to possess 
the same external aperture that occurs in the herring, but I cannot 
find any trace of it among the Salmonide. As far as regards the 
members of this family with which I am acquainted (and I know 
a good many of them) I should certainly say that they were very 
“‘hard of hearing” indeed. I am alluding now to sounds made 
in the air and not in the water. I have often had the opportunity 
of testing the matter, as for instance, in the case of firing a gun 
close to the fish, and in many other ways. If they see nothing 
they take not the slightest notice. 
Livingstone Stone, the great American authority, is also very 
much of the same opinion, and says in his Domesticated Trout 
(p. 221) :—“T will not say that trout cannot hear; but this I will 
say with the greatest positiveness, for I have tested it repeatedly, 
that they are not frightened at noises, however loud, nor do they 
pay the slightest attention to them. You may place your mouth 
directly over the trout in a pond, and, if they do not see you, you 
may scream with all your might, or ring a bell as loud as 
you please, and the trout will not move a fin to show that they 
are either frightened or attracted, or that they have in any way 
‘noticed it.” 
Seth Green, in his Zrout Culture (p. 58), says that trout 
cannot hear, and that ‘they will not stir a fraction of an inch at 
the sound of a gun fired one foot above their heads.” This is, of 
course, provided they see no flash or smoke. With regard to the 
