HISTORY OF THE PARROTS. 
75 
minent to shew that its relationship to the other 
Bcansorial groups is of a degree much nearer than 
what it bears to any other tribe : and farther, that 
its apparent isolation, or want of a still closer con- 
nexion with the birds among which it is placed, in 
all probability arises, merely from the circumstance 
that the species necessary to fill up this chasm oi 
deficiency of connecting forms, though existing, re- 
main yet to be discovered either in it or the conter- 
minous families of the tribe. Previous to the en- 
lightened and philosophic views of recent naturalists 
respecting systematic arrangement, and the discovery 
that all natural groups, of whatever value or extent 
they may be, arrange themselves in a circular form, 
or shew a disposition to return into themselves, the 
parrots, under the Linntean and other artificial sy— 
terns, were considered as forming a single isolated 
genus, under the title of Psittacus, the various mo- 
difications of form they exhibited being only consi- 
dered in the light of specific characters, or at most 
used for arbitrary sectional division. A comparison, 
however, of the parrots with other extensive groups, 
and a due consideration of the great diversity of form, 
as well as of habits and manners, observed to prevail 
among them, plainly shews that they are entitled to 
a rank much higher or more comprehensive than 
that of Genus, which, according to the now gene- 
rally received acceptation of the term, is used to de- 
signate one of the lowest assemblages of individuals 
or species. In consequence, the Linntean genus, 
