79 
BIRDS WITH QUEER BEAKS 
call for special comment on account of the 
enormous size of their beaks, and of these the 
hornbills are especially noticeable owing to 
their bills frequently being decorated with 
a casque or helmet-like protuberance, of vary¬ 
ing shape and size, that arises from the upper 
mandible. 
One of the most remarkable of these birds 
is the rhinoceros hornbill which possesses a 
casque furnished with an upturned and horn-like 
growth that suggests the horn of a rhinoceros. 
In nearly all instances these enormous 
casques are by no means so heavy as they 
look, the interior being composed of a net¬ 
work of cellular structures. That of one 
species, however, is solid throughout, and 
of considerable weight. Indeed, so similar 
is it in appearance and consistency to ivory, 
that the Chinese frequently make use of it 
as a basis for their carvings. 
Although these gigantic beaks act as most 
efficient weapons of defence and offence, and 
can but receive the respect due to them from 
any adversary rash enough to come within 
striking distance thereof, yet they are believed 
to serve an additional purpose, the cellular 
interior acting as a resonator, and increasing 
the volume of the bird’s cry, which is excep¬ 
tionally loud. 
