40 
SYSTEM OF NATURE. 
man himself: its large brain and peculiar tact in imitation 
are still additional similarities. I should, therefore, place 
the genus Psittacus as one of the Primates among birds. 
2ndly. The Rapacia. The dog tribe — I more particu¬ 
larly allude to the wolf or hyaena, for the dog is almost un¬ 
known in a state of nature,—are greedy in the extreme: they 
fill themselves with carrion ; they tear open graves to devour 
the putrifying bodies of the dead; they scent their dis¬ 
gusting food at a distance, and crowd to it from all direc¬ 
tions : these are the very characters of the vulture. The 
genera Felis and Falco in like manner correspond in their 
thirst for blood and in their pursuit o*f living prey. I there¬ 
fore consider the vulture and eagle as the Ferae among birds. 
3rdly. The Volitantia. They are nocturnal, constantly 
on the wing; they feed on nocturnal insects, caught as they 
fly. The same characters are those of the goat-suckers : 
the swallows would appear to be the diurnal analogues of 
bats ; they differ only in flying by day instead of by night: 
therefore I look on goat-suckers and swallows as bats 
among birds, and 1 am not certain that the owls do not 
belong here rather than to the Rapacia. I should consider 
goat-suckers and swallows as bats among birds : they are 
preeminently flying birds. 
4thly. The Saltantia. The rats, mice, squirrels, &c.: 
these feed on a variety of substances; seeds, particularly 
com, fruits of all kinds, insects, sometimes on small birds, 
or small animals of their own kind : many of them are re¬ 
markable for their attachment to the residences of man : 
they perforate our walls, make their nests and bring forth 
their young in holes and crevices of our roofs, wainscots or 
ceilings ; they devour our bread, cheese, lard, bacon, vege¬ 
tables, and almost every nutritious substance to which they 
