18 Royal Avenue Terrace | Chelsea. SW.
2 Decr. 1862.
My dear Sir,
I have just turned out another domestic animal which I had laid aside for you—a Guinea Pig.1 It is of the Chinese breed, and may perhaps be interesting to you for comparison with the European bred animals. I heard it asserted the other day at Cambridge that the domestic Guinea-pig would not interbreed with the Rock Cavy, it’s supposed parent-stock, and that consequently a new species had been formed by artificial selection. Have you heard of this asserted fact?2 The person that gave it forth at Cambridge had it I believe on good authority. I should like much to hear your opinion on this subject.
I remain, | Dear Sir, | Your’s very truly,
Robert Swinhoe
Charles Darwin, Esqre.
Please cite as “DCP-LETT-3842,” in Ɛpsilon: The Charles Darwin Collection accessed on