I do not look at this as mere analogy.

I would as soon believe that fossil shells were mere mockeries of real shells as that the same bones in the foot of a dog and wing of a bat, or the similar embryo of mammal and bird, had not a direct signification, and that the signification can be unity of descent or nothing.

But I venture to repeat how much pleased I am that you go some little way with me.

I find a number of naturalists do the same, and as their halting-places are various, and I must think arbitrary, I believe they will all go further.

As for changing at once one's opinion, I would not value the opinion of a man who could do so; it must be a slow process.