My dear Mr Darwin

I am exceedingly sorry that I should have given you the trouble of writing again about the goose’s wing—but it came to me just as I was beginning a course of Lectures which occupied very much time.—¹

When they were over I went into the Country for a week, and since I came back I have had a quantity of arrears to fetch up. In the meanwhile the wing has been macerating in water, and only just got into a condition soft enough to enable me to examine it properly

I send you a sketch of the malformation (if it can be so called) on the back of Mr Blairs Letter.²

The bones are all perfectly normal but the digits (with the large primary feathers) were in the dried state of the wing abnormally flexed upon the metacarpus at the metacarpo-phalangeal joint   Normally these bones would be in a straight line with one another— There is nothing in the bones to account for this and when softened there is no difficulty in replacing them in the natural position   The malformation of the bones was probably due to want of balance in the contractile power of opposing muscles & is analogous to club-foot in man.³

Supposing this view is correct (and it ought to be verified by dissections of the muscles and tendons in a recent state in several specimens) it is interesting in connection with the history, as although the particular injury of the parent has not reproduced itself in the offspring—it may probably have led to some disturbance in the functions of the nerves which control the muscles of the same region in this case. Of course this seems very far fetched: but unless it is a mere coincidence it is the only way in which I can account for the circumstance

Before saying more I should like to have several of the wings, especially of very young birds, examined to see whether the condition was the same in all, or whether congenital, or acquired after birth. The wing of the original goose ought also to be examined and described to make the story complete. I think that on the whole it is worth following up—

Believe me | Yours very truly | W H Flower

W. H. Flower