From David Forbes   [after 11 December 1860]¹

and is about finished—

The question you ask me about the glacial action I can only answer as follows—²

From Lat. 13^o to lat 30^o there is a plateau or rather indistinct remains of one at about 12000 feet elevation composed of debris such as would generally be ascribed to ice action— the rocks are in many parts especially lat 15^o 16^o. 17^o. 18^o S. strongly furrowed & grooved similar to those of Norway.³ the grooves have a general direction and the debris from the plateau in question contains rolled and marked or grooved & scratched pebbles— down where you observed the mass of debris in question,⁴ the remains of the plateau is only distinct in spots evidently from the river action, but only some 15 leagues north of same I found it grandly developed—and could not explain it at all untill my later examination of the chain of the Andes northward up to Lat 13. showed me at spots (barometrical measurements) a similar development connecting same with the great Eastern Andean plateau of Silurian debris, described in section—   I was informed that a little south of Cauquenes, there exist real glaciers in the Andes—but I found none north of same—   my information was tolerably reliable

As I believe fully in your theory of the origin of species I shall be glad to do anything for you in advancing same and shall attend to the questions you send me and send you answers as soon as possible    If you have more points I shall attend to them if you drop me a line—   The question you ask me about the Chilean breed of sheep—I can in part answer now—⁵

I was also struck with this and at 2 haciendas I staid at endeavoured to come to the bottom of this but not satisfactorily.— The prevalent opinion is that the race was originally derived from an intermixture of sheep & goat but as far as I could discover, it is nowhere now produced from this source—and the flocks at all the haciendas I saw are only ofspring of similar sheep and not artificially produced as the mules—   One Haciendado at Mendoza stated that, altho if I asked every other Haciendado—in the province they would tell me it was a cross he never knew such a case to have actually occurred & stated his belief that they were a distinct race of sheep

One would think it had been easy to have sifted such a simple question but I did not succed—   would an examination (microscopic) of the hair be of service—   I could send you some as I have a saddle cover here in Birmingham of this article.—⁶

There is one point I would direct your attention to    it is the horse— The horse of S America was originally Spanish or Andalusian—but now presents 3 wonderfully different variety

1. Chilian—exactly same as true Andalusian

2. Pampa horse    you know

3. Puno horse—a most strange sort of small horse, slender narrow chested & very peculiar altogether—evidently owing to the rarified atmosphere—⁷ I believe I can prove a great change from same cause in the Puno Indians (Aymara) whom I found to be structurally different. for example femur longer than tibia, &c.⁸

Yours very truly | David Forbes