I have always looked at the doctrine of Natural Selection as an hypothesis, which, if it explained several large classes of facts, would deserve to be ranked as a theory deserving acceptance; and this, of course, is my own opinion.

But, as Huxley has never alluded to my explanation of classification, morphology, embryology, etc., I thought he was thoroughly dissatisfied with all this part of my book.

But to my joy I find it is not so, and that he agrees with my manner of looking at the subject; only that he rates higher than I do the necessity of Natural Selection being shown to be a vera causa always in action.

He tells me he is writing a long review in the "Westminster." It was really provoking how he wasted time over the idea of a species as exemplified in the horse, and over Sir J.Hall's old experiment on marble.

Murchison was very civil to me over my book after the lecture, in which he was disappointed.