246 
towards the preservation of the individuals by which it was 
employed. If an outcry increased the chance of victory in 
combat, the inclination and ability to exclaim would become 
permanent, and cries would be habitually uttered in the tones 
most easily produced, or most effectual in its result. 
My suggestion that voice was produced by contortion was 
founded on my own observations on the three common newts 
and the snake. The newts are always silent unless writhing 
in the grasp of some enemy, upon which occasion a distinct 
croaking sound is emitted. Air is retained in their lungs, as in 
those of snakes, by the contraction of the glottis: hence, in 
both animals, the escape of air from the lungs is attended with 
some frictional vibration at this point. 
In Vol. 1 of “The Naturalists’ World,” pp. 160 and 180, 
will be found letters from four persons who had heard newts 
squeak when held with the fingers. Under other conditions the 
newt is silent. Further, on two occasions I have heard an 
immature frog, which could not croak, scream when seized by 
a snake; and here we have another instance of vocal sound 
being first produced during what may be termed combat. 
Darwin says (“ Expression of Emotions,” p. 83), “‘ When 
the sensorium is strongly excited, the muscles of the body are 
generally thrown into violent action; and as a consequence, 
loud sounds are uttered, however silent the animal may 
generally be, and although the sound may be of no use. 
Hares and rabbits, for instance, never, I believe, use their 
vocal organs except in the extremity of suffering; as when a 
wounded hare is killed by a sportsman, or when a young rabbit 
is caught by a stoat. Cattle and horses suffer great pain in 
silence, but when this is excessive, and especially when 
associated with terror, they utter fearful sounds, (Page 84). 
Involuntary and purposeless contractions of the muscles of 
the chest and glottis, excited in the above manner, may have 
first given rise to the emission of vocal sounds.” 
It may be remarked generally that animals do not, when 
enduring internal pain, utter vocal sounds, unless such may 
possibly be of use; they are silent when poisoned: hence we 
-T ~~ 
