enjoyed the tremendous rap on the knuckles which you gave Virchow
at the close. What a pleasure it must be to write as you can do!

LETTER 295. TO E.S. MORSE. Down, October 21st, 1879.

Although you are so kind as to tell me not to write, I must just thank
you for the proofs of your paper, which has interested me greatly.
(295/1. See "The Shell Mounds of Omori" in the "Memoirs of the Science
Department of the Univ. of Tokio," Volume I., Part I., 1879. The ridges
on Arca are mentioned at page 25. In "Nature," April 15th, 1880, Mr.
Darwin published a letter by Mr. Morse relating to the review of the
above paper, which appeared in "Nature," XXI., page 350. Mr. Darwin
introduces Mr. Morse's letter with some prefatory remarks. The
correspondence is republished in the "American Naturalist," September,
1880.) The increase in the number of ridges in the three species of Arca
seems to be a very noteworthy fact, as does the increase of size in so
many, yet not all, the species. What a constant state of fluctuation
the whole organic world seems to be in! It is interesting to hear that
everywhere the first change apparently is in the proportional numbers of
the species. I was much struck with the fact in the upraised shells of
Coquimbo, in Chili, as mentioned in my "Geological Observations on South
America."

Of all the wonders in the world, the progress of Japan, in which you
have been aiding, seems to me about the most wonderful.

LETTER 296. TO A.R. WALLACE. Down, January 5th 1880.

As this note requires no sort of answer, you must allow me to express
my lively admiration of your paper in the "Nineteenth Century." (296/1.
"Nineteenth Century," January 1880, page 93, "On the Origin of Species
and Genera.") You certainly are a master in the difficult art of clear
exposition. It is impossible to urge too often that the selection from a
single varying individual or of a single varying organ will not suffice.
You have worked in capitally Allen's admirable researches. (296/2. J.A.
Allen, "On the Mammals and Winter Birds of East Florida, etc." ("Bull.
Mus. Comp. Zoolog. Harvard," Volume II.) As usual, you delight to honour
me more than I deserve. When I have written about the extreme slowness
of Natural Selection (296/3. Mr. Wallace makes a calculation based on
Allen's results as to the very short period in which the formation of a
race of birds differing 10 to 20 per cent. from the average in length of
wing and strength of bea