€hap. XIX. 
MUSICAL POWEES. 
331 
stridulating organs, whicli are often confined to the 
males alone. The sounds thus produced consist, I believe 
in all cases, of the same note, repeated rhythmically ; 
and this is sometimes pleasing even to the ears of man. 
Their chief, and in some cases exclusive use appears to 
be either to call or to charm the opposite sex. 
The sounds produced by fishes are said in some cases 
to be made only by the males during the breeding 
:season. All the air-breathing Yertebrata necessarily 
possess an apparatus for inhaling and expelling air, with 
u pipe capable of being closed at one end. Hence when 
the primeval members of this class were strongly ex- 
cited and their muscles violently contracted, purpose- 
less sounds would almost certainly have been produced ; 
and these, if they proved in any way serviceable, might 
readily have been modified or intensified by the pre- 
.servation of properly adapted variations. The Amphi- 
bians are the lowest Vertebrates which breathe air ; and 
many of these animals, namely, frogs and toads, possess 
vocal organs, which are incessantly used during the 
breeding- season, and which are often more highly 
developed in the male than in the female. The male 
alone of the tortoise utters a noise, and this only during 
the season of love. Male alligators roar or bellow 
during the same season. Every one knows how largely 
birds use their vocal organs as a means of courtship ; 
and some species likewise perform what may be called 
instrumental music. 
In the class of Mammals, with which we are here 
more particularly concerned, the males of almost all the 
species use their voices during the breeding-season 
much more than at any other time ; and some are abso- 
Dr. Scudder, Notes on Stridulation,” in ’Proc. Boston Soc. of 
Nat. Hist.’ vol. xi. April, 1S68. 
