Darwin Correspondence Project

25. Sept. 1860

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I return the M.S. on dogs which I think excellent. The case you make out seems very strong not only of crosses from distinct living species having blended into the dog, but in favour of difft savage races having domesticated different canine types, wolves, jackalls &c by domestication in accordance with the hypothesis of Pallas having eliminated the dislike to cross with other species as well as the tendency of such crosses to sterility.

All this helps the doctrine of the several so blendible wild species having themselves come down from a common remote progenitor & I suppose you will say in reply to Quart. Review that the only reason that pigeons have not so mixed is that Man had not the same motive to cross them with other species distinct from the Rock pigeon.

I think the subject too important to bear shortening. As to the antiquity of the Dingo I have turned up to your two references in Quart. G. S. Journal & they by no means bear out your inference. The fossils occurred in a cave in the basalt & were certainly posterior probably very long so, & there is no evidence as caves are gradually choked up that the Dingo was not one of the last creatures whose bones were introduced. I asked Falconer yesterday & he said, `let him take care he does not get himself into the same scrape which Owen did about Strzelecki's Australian Mastodon; I read the papers about Dingo & thought they had no proof.'

Falconer knows of no fossil, rodent or bat in Australia. He says Strzelecki's Mastodon was from S. America.

It seems strange that the question whether any Newfoundland dogs are semi-web-footed or not shd be so doubtful, also gestation of jackall. On these and many points yr book will draw forth a number of facts for the 2d. Edn.

Some one shd go at once to Angoulˆeme & see into that question of the Leporine. If true, it wd. take away the antecedent improbability of Pallas' hypothesis of dogs when domesticated losing sterility &c. Bartlett says, at Zool. Gardens, that we must wait till next spring for good experiments. He ought to have as many as possible to start with.

The chapter on dogs makes me wish yr book soon out. That & the pigeons & the Tables of large & small genera wd alone make a useful beginning.

You conclude yr. letter received this morning by doubting whether I care for so speculative a way of dealing with the question. It is just what I wanted & not more conjectural than my letter, much of which I wd not of course touch or venture on in print, nor wish shown to third persons, more especially as one may alter one's speculations the day after. I have referred to the pp. you allude to of Origin with much profit, tho` I remembered them all, but they contain such a condensation of matter that they require to be often re-read.

I have been too deeply interested & taken up with the Dogs to have done with Asa Gray, but see enough to wish it to appear in Annals of N. H. & cannot but think they wd print it for their own sake & not require you to pay. Tell them that the addition of A. Gray's name wd give a wholly new value to it instead of its appearing anonymously    I want to buy it, for one.

I think you have understood my point & the idea that if the original type of Mammalia had been lost & the reptilian had been greatly raised in grade, they wd. have produced some other great class as high perhaps or higher but not the existing Mammalia, is a grand notion & believing as I do in the infinite Capacity of the creative power, inherent in the organic world, worked out by variation & natural selection, I do not think it an extravagant speculation at all. You might say the same if some monotreme, instead of a reptile, was improved into a mammal, by a series of changes independent of those which gave rise to the first mammal. Possibly birds may be an instance of such a class, though I fear that would not do, because however low the Monotreme, it must perhaps rank typically before birds & birds therefore must have preceded in order of development.

I am glad you reminded me of the N. Guinea Marsupials. I had imagined that there was a larger admixture of placentals. I shd. think still the Australian genera & species were so well fitted for the extraordinary droughts that they wd. get the better of the Dingo had he run wild as in Juan Fernandez. The Brazilian case does not tell for much as that country has in the Marsupial line turned out nothing but opossums.

The case of natl. grafting stated by G¨oppert ¨Uberwallung der Tannenst¨oche, Bonn 1842, where silver fir borrows from roots of Pinus abies is the more analogous to grafting as being one conifer borrowing from another.— Plants of other divisions wd do the same probably if near enough to allied trees, which owing to rotation may not be often at hand. If the genus were remote, it wd. fail.

Do you not think when Man was less advanced 50,000 years or generations back & tribes more isolated there must have been rather more races than now. tho' of course at a remoter period much fewer, & originally only one, & that one lower intellectually than any one now existing. In proportion as more powerful & more cosmopolite races arose they wd exterminate inferior ones & also there wd be more mixture & a check to divergence into species or the centripetal force of hybridity (excuse the use of the phrase) would come into play.

Falconer has been holding forth today on the difft, Mastodons & Elephants not coming in chronologically as they shd do, according to yr views, but when one sees the new Maltese dwarf intermediate between E. antiquus & E. meridionalis & Anca's new Sicilian cave elephant, a modification of the living Indian one leaning towards antiquus, & when one thinks that Falconer can distinguish all American varieties of Mammals from all European fossil species, I confess I attach little value to the objection.