As I do not know Mr. Ford's address, will you hand him this note, which is written solely to express my unbounded admiration of the woodcuts. I fairly gloat over them. The only evil is that they will make all the other woodcuts look very poor! They are all excellent, and for the feathers I declare I think it the most wonderful woodcut I ever saw; I can not help touching it to make sure that it is smooth. How I wish to see the two other, and even more important, ones of the feathers, and the four [of] reptiles, etc. Once again accept my very sincere thanks for all your kindness. I am greatly indebted to Mr. Ford. Engravings have always hitherto been my greatest misery, and now they are a real pleasure to me. Yours very sincerely, CH. DARWIN. P.S.--I thought I should have been in press by this time, but my subject has branched off into sub-branches, which have cost me infinite time, and heaven knows when I shall have all my MS. ready, but I am never idle. CHARLES DARWIN TO A. GUNTHER. May 15 [1870]. My dear Dr. Gunther, Sincere thanks. Your answers are wonderfully clear and complete. I have some analogous questions on reptiles, etc., which I will send in a few days, and then I think I shall cause no more trouble. I will get the books you refer me to. The case of the Solenostoma (In most of the Lophobranchii the male has a marsupial sack in which the eggs are hatched, and in these species the male is slightly brighter coloured than the female. But in Solenostoma the female is the hatcher, and is also the more brightly coloured.--'Descent of Man,' ii. 21.) is magnificent, so exactly analogous to that of those birds in which the female is the more gay, but ten times better for me, as she is the incubator. As I crawl on with the successive classes I am astonished to find how similar the rules are about the nuptial or "wedding dress" of all animals. The subject has begun to interest me in an extraordinary degree; but I must try not to fall into my common error of being too speculative. But a drunkard might as well say he would drink a little and not too much! My essay, as far as fishes, batrachians and reptiles are concerned, will be in fact yours, only written by me. With hearty thanks. Yours very sincerely, CH. DARWIN. [The following letter is of interest, as showing the excessive care and pains which my father took in forming his opinion on a difficult point:] CHARLES DARWIN TO A.R. WALLACE. Down, September 23 [undated]. My dear Wallace,