I am not
at all shaken, and stick to my colours like a true Briton. When I think
about the unadorned head of the Argus pheasant, I might exclaim, _Et tu,
Brute!_

* * * * *

_Down, Beckenham. June 25, 1876._

My dear Wallace,--I have been able to read rather more quickly of late
and have finished your book. I have not much to say. Your careful
account of the temperate parts of South America interested me much, and
all the more from knowing something of the country. I like also much the
general remarks towards the end of the volume on the land molluscs. Now
for a few criticisms.

P. 122:[107] I am surprised at your saying that "during the whole Tertiary
period North America was zoologically far more strongly contrasted with
South America than it is now." But we know hardly anything of the latter
except during the Pliocene period, and then the mastodon, horse, several
great Dentata, etc. etc., were common to the North and South. If you are
right I erred greatly in my Journal, where I insisted on the former
close connection between the two.

P. 252, and elsewhere: I agree thoroughly with the general principle
that a great area with many competing forms is necessary for much and
high development; but do you not extend this principle too far--I should
say much too far, considering how often several species of the same
genus have been developed on very small islands?

P. 265: You say that the Sittidae extend to Madagascar, but there is no
number in the tabular heading.[108]

P. 359: Rhinochetus is entered in the tabular heading under No. 3 of the
_Neotropical_ sub-regions.[109]

Reviewers think it necessary to find some fault, and if I were to review
you, the sole point which I should blame is your not giving very
numerous references. These would save whoever follows you great labour.
Occasionally I wished myself to know the authority for certain
statements, and whether you or somebody else had originated certain
subordinate views. Take the case of a man who had collected largely on
some island, for instance St. Helena, and who wished to work out the
geographical relations of his collection; he would, I think, feel very
blank at not finding in your work precise references to all that had
been written on St. Helena. I hope you will not think me a confoundedly
disagreeable fellow.

I may mention a capital essay which I received a few mouths ago from
Axel Blytt[110] on the distribution