To Asa Gray   11 August [1860]¹

My dear Gray

On my return home from Sussex about a week ago I found several articles sent by you.—   The 1^st article from the Atlantic which I am very glad to possess.² By the way the Editor of Athenæum has inserted your answer to Agassiz, Bowen & Co. & where I therein read them;³ I admired them even more than at first. They really seem to me admirable in their condensation, force, clearness & novelty.

I am surprised that Agassiz did not succeed in writing something better. How absurd that logical quibble;—“if species do not exist how can they vary?”⁴ As if anyone doubted their temporary existence. How coolly he assumes that there is some clearly defined distinction between individual differences & varieties. It is no wonder that a man who calls identical forms when found in two countries distinct species, cannot find variation in nature.⁵ Again how unreasonable to suppose that domestic varieties selected by man for his own fancy (p. 147) sh^d. resemble natural varieties or species. The whole article seems to me poor: it seems to me hardly worth a detailed answer (even if I could do it, & I much doubt whether I possess your skill in picking out salient points & driving a nail into them) & indeed you have already answered several points. Agassiz’s name, no doubt, is a heavy weight against us; but yesterday I heard that a man, whom I believe to be greater than Agassiz, viz Von Baer goes a long way (how far I know not) with me, & has spoken out publickly & will probably publish.⁶ R. Wagner has published, also, in Germany an abstract of Agassiz’s Essay on Classification, & says he believe the truth lies between us two;⁷ & this will make A. very savage, I sh^d. think.—

If you see Prof. Parsons, will you thank him for the extremely liberal & fair spirit in which his Essay is written.—⁸ Please tell him that I reflected much on chance of favourable monstrosities (ie great & sudden variations) arising.⁹ I have, of course, no objection to them; indeed it w^d. be great aid; but I did not allude to subject, for after much labour I could find nothing which satisfied me of the probability of such occurrences. There seems to me in almost every case too much, too complex, & too beautiful adaptation in every structure to believe in its sudden production. I have alluded under head of beautifully hooked seeds to such possibility.¹⁰ Monsters are apt to be sterile, or not to transmit monstrous peculiarities. Look at fineness of gradation in the shells of successive sub-stages of same great formation. I could give many other considerations which made me doubt such view.—   It holds to certain extent with domestic productions no doubt, where man preserves some abrupt change in structure. It amused me to see Sir R. Murchison quoted as a judge of affinities of animals;¹¹ & it gave me a “cold shudder” to hear of anyone speculating about a true Crustacean giving birth to a true Fish.!¹²

Since I wrote last I received your note of July 10^th, in which you confirm the capital pig story:¹³ (I fear Prof. Wyman will never give me his facts about striped Horses)¹⁴    Also you give me valuable hints about diœcio-dimorphous flowers.—¹⁵ I was forced to gather my cowslip seed too soon, & I am all at sea about the differences in fertility; but I shall try & work out case better next summer.—

My poor daughter is decidedly better, though still very ill & weak. But I hope the organic mischief suspected by the Doctors, consequent on the fever, is slowly righting. There was fluid in the abdomen, but this seems to have absorbed; but there is still some hardness. We have had a miserable time of it.—

Farewell my kind friend | Yours most truly | C. Darwin