of such groups occur to me at once, in entomology, in Heliconiidae
and Erotylidae of South America; the latter I think more interesting than
the former for one reason--the species are more local, having feebler
means of locomotion than the Heliconiidae....--Yours very truly,

HENRY WALTER BATES.

* * * * *

TO H.W. BATES

_Amboyna. January 4, 1858._

My dear Bates,--My delay of six months in answering your very
interesting and most acceptable letter dated an ideal absurdity put
forth when such a simple hypothesis will explain _all the facts_.

I have been much gratified by a letter from Darwin, in which he says
that he agrees with "almost every word" of my paper. He is now preparing
for publication his great work on species and varieties, for which he
has been collecting information twenty years. He may save me the trouble
of writing the second part of my hypothesis by proving that there is no
difference in nature between the origin of species and varieties, or he
may give me trouble by arriving at another conclusion, but at all events
his facts will be given for me to work upon. Your collections and my own
will furnish most valuable material to illustrate and prove the
universal applicability of the hypothesis. The connection between the
succession of affinities and the geographical distribution of a group,
worked out species by species, has never yet been shown as we shall be
able to show it. In this Archipelago there are two distinct faunas
rigidly circumscribed, which differ as much as those of South America
and Africa, and more than those of Europe and North America: yet there
is nothing on the map or on the face of the islands to mark their
limits. The boundary line often passes between islands closer than
others in the same group. I believe the western part to be a separated
portion of continental Asia, the eastern the fragmentary prolongation of
a former Pacific continent. In mammalia and birds the distinction is
marked by genera, families, and even orders confined to one region; in
_insects_ by a number of genera and little groups of peculiar species,
the _families_ of insects having generally a universal distribution.

* * * * *

_Ternate, January 25, 1858._

I have not done much here yet, having been much occupied in getting a
house repaired and put in order. This island is a volcano with a sloping
spur on which the town is situated.