The Descent of Man

eptiles and fishes, on the skin of amphibians,
on the wings of many Lepidoptera and other
insects, they deserve to be especially noticed.
An ocellus consists of a spot within a ring of
another colour, like the pupil within the iris,
but the central spot is often surrounded by additional
concentric zones. The ocelli on the tailcoverts
of the peacock offer a familiar example,
as well as those on the wings of the peacockbutterfly
(Vanessa). Mr. Trimen has given me a
description of a S. African moth (Gynanisa isis),
allied to our Emperor moth, in which a magnificent
ocellus occupies nearly the whole surface
of each hinder wing; it consists of a black centre,
including a semi-transparent crescentshaped
mark, surrounded by successive, ochreyellow,
black, ochre-yellow, pink, white, pink,
brown, and whitish zones. Although we do not
know the steps by which these wonderfully
beautiful and complex ornaments have been
developed, the process has probably been a
simple one, at least with insects; for, as Mr.