Chap. XIX. 
MUSICAL POWERS. 
331 
fected in relation to the propagation of the species. 
Insects and some few spiders are the lowest animals 
which voluntarily produce any sound ; and this is gene- 
rally effected by the aid of beautifully constructed 
stridulating organs, which 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 ot 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 
a pipe capable of being closed at one end. cnee w len 
the primeval members of this class were strong y ex- 
cited and then- 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 
27 Dr. Scudder, “ Notes on Stridulation,” in ‘ Proc. Boston Soc. of 
Nat. Hist.’ vol. xi. April, 1868. 
