The Descent of Man

tron the two oval ocelli on the same feather
stand parallel to each other; in other species (as
in P. chinquis) they converge towards one end;
now the partial confluence of two convergent
ocelli would manifestly leave a much deeper
indentation at the divergent than at the convergent
end. It is also manifest that if the convergence
were strongly pronounced and the confluence
complete, the indentation at the convergent
end would tend to disappear.
The tail-feathers in both species of the peacock
are entirely destitute of ocelli, and this apparently
is related to their being covered up and concealed
by the long tail-coverts. In this respect
they differ remarkably from the tail-feathers of
Polyplectron, which in most of the species are
ornamented with larger ocelli than those on the
tail-coverts. Hence I was led carefully to examine
the tail-feathers of the several species, in
order to discover whether their ocelli shewed
any tendency to disappear; and to my great