SUCTORIAL ANIMALS. 963 
upon insects, but lizards and other reptiles; and Azara 
asserts that the Sawrophagus sulphuratus or Bentevi 
fly-catcher of Brazil, actually picks the meat from 
the bones of such carcasses as have been left by the 
larger animals of prey. Such facts are highly 
interesting, and will frequently, as in the bird last 
mentioned, decide a doubtful point in natural ar- 
rangement: it follows, therefore, that omnivorous 
habits furnish characters of great value. 
(181.) There is another mode of taking food, 
very general among the invertebrated animals, but 
not so distinctly marked in the higher classes. We 
allude to suction, by which fluids alone constitute 
the sustenance of the animal. There is a modi- 
fication of this structure of mouth in the ant-eaters, 
and in the honey-sucking birds ( Tenwirostres), 
where the tongue alone is employed to collect food ; 
but the most perfect examples of the suctorial 
structure of mouth are found among the four- 
winged insects, where we find two, entire orders, — 
the Lepidoptera and the Hemiptera, — entirely 
destitute of jaws, and deriving their sole nourish- 
ment from juices, sucked up either by a slender 
jointed trunk, or a long and spirally rolled pro- 
boscis. Nature has evidently made this structure 
a leading distinction of particular groups through- 
out the animal circle, for we find that in every 
class some are suctorial, while others are not; and 
that this habit is always accompanied by a uni- 
formity in the general shape of the rostrum or 
mouth, which, as suited to such functions, is always 
very long and slender. This we see in the ant-eaters, 
s 4 
