I fancy I am right in speaking in this note of the species in common to N.and S.
as being rather sub-arctic than arctic.
This letter does not require any answer.

I have written it to ease myself, and to get you just to bear your argument, under the modification point of view, in mind.

I have had this morning a most cruel stab in the side on my notion of the distribution of mammals in relation to soundings.
LETTER 335.

J.D.HOOKER TO CHARLES DARWIN.

Kew, Sunday [November 1856].
I write only to say that I entirely appreciate your answer to my objection on the score of the comparative rareness of Northern warm-temperate forms in the Southern hemisphere.