HOOKER.
(361/1.

In the earlier part of this letter Mr.Darwin refers to a review on Planchon in the "Nat.

History Review," April 1865.

There can be no doubt, therefore, that "Thomson's article" must be the review of Jordan's "Diagnoses d'especes nouvelles ou meconnues," etc., in the same number, page 226.

It deals with "lumpers" and "splitters," and a possible trinomial nomenclature.) April 17th [1865].
I have been very much struck by Thomson's article; it seems to me quite remarkable for its judgment, force, and clearness.