Chapter IX. (192/2. Chapter IX., "Theory of the Progressive Development

of Organic Life at Successive Geological Periods."), and like it

extremely; it all seems to me very clear, cautious, and sagacious. You

do not allude to one very striking point enough, or at all--viz., the

classes having been formerly less differentiated than they now are;

and this specialisation of classes must, we may conclude, fit them

for different general habits of life as well as the specialisation of

particular organs.

Page 162 (192/3. On page 163 Lyell refers to the absence of Cetacea

in Secondary rocks, and expresses the opinion that their absence "is a

negative fact of great significance, which seems more than any other to

render it highly improbable that we shall ever find air-breathers of

the highest class in any of the Primary strata, or in any of the older

members of the Secondary series.") I rather demur to your argument from

Cetacea: as they are such greatly modified mammals, they ought to have

come in rather later in the series. You will think me rather impudent,

but the discussion at the end of Chapter IX. on man (192/4. Loc. cit.,

pages 167-73, "Introduction of Man, to what extent a Change of the

System."), who thinks so much of his fine self, seems to me too long, or

rather superfluous, and too orthodox, except for the beneficed clergy.

LETTER 193. TO V. CARUS.

(193/1. The following letter refers to the 4th edition of the "Origin,"

1866, which was translated by Professor Carus, and formed the 3rd German

edition. Carus continued to translate Darwin's books, and a strong

bond of friendship grew up between author and translator (see "Life and

Letters," III., page 48). Nageli's pamphlet was first noticed in the 5th

English edition.)

Down, November 21st, 1866.

...With respect to a note on Nageli (193/2. "Entstehung und Begriff der

Naturhistorischen Art," an Address given before the Royal Academy of

Sciences at Munich, March 28th, 1865. See "Life and Letters," III.,

page 50, for Mr. Darwin's letter to the late Prof. Nageli.) I find on

consideration it would be too long; for so good a pamphlet ought to be

discussed at full length or not at all. He makes a mistake in supposing

that I say that useful characters are always constant. His view about

distinct species converging and acquiring the same identical structure

is by implication answered in the discussion which I have given on the

endless diversity of means for gaining the same end.

The most important point, as it seems to me, in the pamphlet is that on

the morphological characters of plants, and I find I could not answer

this without going into much detail.

The answer would be, as it seems to me, that important morphological

characters, such as the position of the ovules and the relative position

of the stamens to the ovarium (hypogynous, perigynous, etc.) are

sometimes variable in the same species, as I incidentally mention when

treating of the ray-florets in the Compositae and Umbelliferae; and I

do not see how Nageli could maintain that differences in such characters

prove an inherent tendency towards perfection. I see that I have

forgotten to say that you have my fullest consent to append any

discussion which you may think fit to the new edition. As for myself I

cannot believe in spontaneous generation, and though I expect that at

some future time the principle of life will be rendered intelligible, at

present it seems to me beyond the confines of science.

LETTER 194. TO T.H. HUXLEY. Down, December 22nd [1866?].

I suppose that you have received Hackel's book (194/1. "Generelle

Morphologie," 1866.) some time ago, as I have done. Whenever you have

had time to read through some of it, enough to judge by, I shall be very

curious to hear your judgment. I have been able to read a page or two

here and there, and have been interested and instructed by parts. But my

vague impression is that too much space is given to methodical details,

and I can find hardly any facts or detailed new views. The number of new

words, to a man like myself, weak in his Greek, is something dreadful.

He seems to have a passion for defining, I daresay very well, and for

coining new words. From my very vague notions on the book, and from its

immense size, I should fear a translation was out of the question. I see

he often quotes both of us with praise. I am sure I should like the book

much, if I could read it straight off instead of groaning and swearing

at each sentence. I have not yet had time to read your Physiology

(194/2. "Lessons in Elementary Physiology," 1866.) book, except one

chapter; but I have just re-read your book on "Man's Place, etc.," and

I think I admire it more this second time even than the first. I doubt

whether you will ever have time, but if ever you have, do read the

chapter on hybridism in the new edition of the "Origin" (194/3. Fourth

Edition (1866).), for I am very anxious to make you think less seriously

on that difficulty. I have improved the chapter a good deal, I think,

and have come to more definite views. Asa Gray and Fritz Muller (the

latter especially) think that the new facts on illegitimate offspring of

dimorphic plants, throw much indirect light on the subject. Now that

I have worked up domestic animals, I am convinced of the truth of

the Pallasian (194/4. See Letter 80.) view of loss of sterility under

domestication, and this seems to me to explain much. But I had no

intention, when I began this note, of running on at such length on

hybridism; but you have been Objector-General on this head.

LETTER 195. TO T. RIVERS.

(195/1. For another letter of Mr. Darwin's to him see "Life and

Letters," III., page 57.)

Down, December 23rd [1866?].

I do not know whether you will forgive a stranger addressing you.

My name may possibly be known to you. I am now writing a book on the

variation of animals and plants under domestication; and there is one

little piece of information which it is more likely that you could give

me than any man in the world, if you can spare half an hour from your

professional labours, and are inclined to be so kind. I am collecting

all accounts of what some call "sports," that is, of what I shall call

"bud-variations," i.e. a moss-rose suddenly appearing on a Provence

rose--a nectarine on a peach, etc. Now, what I want to know, and

which is not likely to be recorded in print, is whether very slight

differences, too slight to be worth propagating, thus appear suddenly

by buds. As every one knows, in raising seedlings you may have every

gradation from individuals identical with the parent, to slight

varieties, to strongly marked varieties. Now, does this occur with

buds or do only rather strongly marked varieties thus appear at rare

intervals of time by buds? (195/2. Mr. Rivers could not give a decided

answer, but he did not remember to have seen slight bud-variations. The

question is discussed in "Variation under Domestication," Edition II.,