Hooker writes: "Some of the most conspicuous trees attain either of its banks, but do not cross them.") in N.E.Europe, on the opposite banks of which the flora was, on the same soil and under same climate, widely different! I forget (14/4.

The last paragraph is published in "Life and Letters," II., page 29.) my last letter, but it must have been a very silly one, as it seems I gave my notion of the number of species being in great degree governed by the degree to which the area had been often isolated and divided.

I must have been cracked to have written it, for I have no evidence, without a person be willing to admit all my views, and then it does follow.
(14/5.

The remainder of the foregoing letter is published in the "Life and Letters," II., page 29.

It is interesting as giving his views on the mutability of species.