ANIMAL CURIOSITIES 
18 • 
sufficient to account for their ability to pro¬ 
duce the large volume of sound for which they 
are famous, and we find that, in addition, 
they are endowed with a series of air sacs or 
resounding chambers that extend along the 
front and sides of the neck, and serve to in¬ 
tensify the notes they utter. 
We are all of us familiar with those remark¬ 
able flying mammals called bats, but how 
many of us can state whether they ever give 
voice to any cry ? 
In all probability the majority of people 
are under the impression that they are quite 
dumb, but such is not the case, for even when 
on the wing they will emit cries which, however, 
are pitched in such a high key as to be quite 
inaudible to many human beings, although 
clearly heard by others whose power of hearing 
is more highly developed and attuned for the 
reception of such notes. 
Among the dog family we find the voice of 
the African hunting-dog is very peculiar and 
consists of three distinct cries, each of which is 
uttered on special occasions. When one of 
the creatures catches sight of a strange object 
that it is unable to understand, it gives vent 
to a short bark, but, according to a well-known 
naturalist and explorer, during the night-time 
“. . . when large numbers of them are together, 
