[The next year, immediately before taking Sir Wyville Thomson's lectures at Edinburgh, he writes about another article which he had in hand:—]

4 Marlborough Place, N.W., March 16, 1875.

My dear Baynes,

I am working against time to get a lot of things done—amongst others BIOLOGY—before I go north. I have written a large part of said article, and it would facilitate my operation immensely if what is done were set up and I had two or three proofs, one for Dyer, who is to do part of the article.

Now, if I send the manuscript to North Bridge will you swear by your gods (0—1—3—1 or any greater number as the case may be) that I shall have a proof swiftly and not be kept waiting for weeks till the whole thing has got cold, and I am at something else a hundred miles away from Biology?

If not I will keep the manuscript till it is all done, and you know what that means.

Ever yours very truly,

T.H. Huxley.

Cragside, Morpeth, August 12, 1875.

My dear Baynes,