Though correspondence has never ebbed so low, CD is constantly in his thoughts.

Observations on cheetahs used as domesticated hunting animals.

Finds geographical barriers sometimes separate species, but also finds species that remain separate where there are no barriers to migration.

Colour "individuates" isolated animal species.

Plains and alpine animal distribution show altitude not strictly analogous to latitude.

Impact of timber cutting on climate has led to extinction of crocodiles.

Will discuss coal formation in letter to Edward Forbes.

CD often asked whether isolated mountains in southern latitudes had closely allied representatives of Arctic and north temperate plants; JDH has found a representative barberry.

Making for Darjeeling via Calcutta.