ct
affinity. The tailless females exhibit simple variability, scarcely two
being found exactly alike even in the same locality. The males of the
island of Borneo exhibit constant differences of the under surface, and
may therefore be distinguished as a local form, while the continental
specimens, as a whole, offer such large and constant differences from
those of the islands, that I am inclined to separate them as a distinct
species, to which the name P. Androgeus (Cramer) may be applied. We
have here, therefore, distinct species, local forms, polymorphism, and
simple variability, which seem to me to be distinct phenomena, but which
have been hitherto all classed together as varieties. I may mention that
the fact of these distinct forms being one species is doubly proved. The
males, the tailed and tailless females, have all been bred from a single
group of the larvae, by Messrs. Payen and Bocarme, in Java, and I myself
captured, in Sumatra, a male P. Memnon, and a tailed female P. Achates,
under circumstances which led me to class them as the same species.

Papilio Pammon offers a somewhat similar case. The female was described
by Linnaeus as P. Polytes, and was considered to be a distinct species
till Westermann bred the two from the same larvae (see Boisduval,
"Species General des Lepidopteres," p. 272). They were therefore classed
as sexes of one species by Mr. Edward Doubleday, in his "Genera of
Diurnal Lepidoptera," in 1846. Later, female specimens were received
from India closely resembling the male insect, and this was held to
overthrow the authority of M. Westermann's observation, and to
re-establish P. Polytes as a distinct species; and as such it
accordingly appears in the British Museum List of Papilionidae in 1856,
and in the Catalogue of the East India Museum in 1857. This discrepancy
is explained by the fact of P. Pammon having two females, one closely
resembling the male, while the other is totally different from it. A
long familiarity with this insect (which replaced by local forms or by
closely allied species, occurs in every island of the Archipelago) has
convinced me of the correctness of this statement; for in every place
where a male allied to P. Pammon is found, a female resembling P.
Polytes also occurs, and sometimes, though less frequently than on the
continent, another female closely resembling the male: while not only
has no male specimen of P. Polytes yet been discovered, but the female
(Poly