When I reached England in the spring of 1862, I found myself
surrounded by a room full of packing cases containing the
collections that I had, from time to time, sent home for my
private use. These comprised nearly three thousand birdskins of
about one thousand species, at least twenty thousand beetles and
butterflies of about seven thousand species, and some quadrupeds
and land shells besides. A large proportion of these I had not
seen for years, and in my then weakened state of health, the
unpacking, sorting, and arranging of such a mass of specimens
occupied a long time.

I very soon decided that until I had done something towards
naming and describing the most important groups in my collection,
and had worked out some of the more interesting problems of
variation and geographical distribution (of which I had had
glimpses while collecting them), I would not attempt to publish
my travels. Indeed, I could have printed my notes and journals at
once, leaving all reference to questions of natural history for a
future work; but, I felt that this would be as unsatisfactory to
myself as it would be disappointing to my friends, and
uninstructive to the public.

Since my return, up to this date, I have published eighteen
papers in the "Transactions" or "Proceedings of the Linnean
Zoological and Entomological Societies", describing or
cataloguing portions of my collections, along with twelve others
in various scientific periodicals on more general subjects
connected with them.