34 DIVISION I. VERTEBRAL ANIMALS.— CLASS II. AVES. 
and sudden winds which arise so unexpectedly between the tropics, and blow 
so violently. The Europeans established at the Moluccas think that the 
furrows, which are seen on the bill of the Hornbills, are the result of age, 
and that each furrow signifies a year, whence the name of Jerarvogel, which 
they give to these birds.” 
Mr. Swainson remarks that the Hornbills are gregarious, noisy birds, gen- 
erally of a very large size, and are restricted to the Old World; that they 
are omnivorous, feeding both on animals and vegetables; that some, how- 
ever, seem only to partake of the latter food, while others, upon the author- 
ity of Le Vaillant, feed upon carrion. 
The Buceros cavatus, dissected by Mr. Owen, was observed to be more 
attached to animal than to vegetable food, and would quit any other sub- 
stance if a dead mouse was offered to it. This it would swallow entire, after 
squeezing it twice or thrice with the bill, and no castings were noticed. Mr. 
Owen, however, adds, that Petiver has borne testimony to its regurgitating 
habits. 
The progressive motion of these birds is by hopping or jumping along. 
Major General Hardwicke expresses surprise at this, and at their perching 
with such security, as their feet are formed for walking, and better suited to 
an error which the consideration of the form, 
the ground than the trees 
and shortness of the tarsi, the structure of the toes, and the general contour 
of the birds might, one would think, have prevented. 
Active and alert, notwithstanding the magnitude of their beaks, these 
birds lightly traverse the branches of the forest, and leap from one to an- 
other, till the highest is attained; they then often stop and utter a loud, 
roaring sound, which may be heard at a considerable distance, and is alarm- 
ing to those who do not know whence it proceeds. The noise thus uttered, 
and which is, most probably, their call-note, throws a light upon the design 
of the hollow protuberance surmounting the bill: it acts as a sounding- 
board, increasing the reverberation of the air. With regard to the huge 
beak itself, many conjectures have been entertained as to its peculiar uses. 
It has been suggested as a reason for its development, that it perhaps con- 
stitutes a necessary weapon of defence against monkeys and other animals 
which may seek to assail its nest, while some have supposed that it might be 
employed in dragging snakes and lizards from their lurking-places, or young 
alates =| fo) 
birds and eggs from the recesses of the trunks of aged trees. 
The Crowned Tock (Luceros coronatus) was found by Le Vaillant, asso- 
ciating in flocks of over five hundred in number in Africa, feeding on the 
remains of an elephant which had been slain by the hunters. They mani- 
fested no alarm at the approach of observers, but continued their feast 
without interruption. 
