My dear Sir

About seven years ago I wrote to you on some matter which I thought might be of interest and received so kind a reply that it encourages me again to trouble you on a subject which may have some scientific importance¹

I went some days since in company with D^r Colbourne² Resident Physician of the British Hospital to see an animal exhibited here as an eightlegged horse which appears to us a remarkable instance of reversion   On the inside of each leg from the knee down is a distinct digit (or whatever the correct term may be) terminating in a perfect hoof   On the fore legs it hangs rather loosely but on the hind the distinct bone is clearly traceable from the knee down with the articulations well defined

It corresponds with the figure of the leg of the Miohippus given in Huxley’s American Addresses Page 88 but is larger reaching close to the ground and more approaching the Architerium of Oscar Schmidts Doctrine of Descent Page 274 Fig P there being however only one additional hoof on each leg.³ It is said that when the horse gallops all eight hoofs touch the ground

We could perceive nothing else abnormal about him   The teeth are of the usual number but the animal is old and has lost his marks so that the form of the surface was not very distinguishable. There appeared nothing uncommon in the skull. Although exhibited here as coming from Chili the horse was bred in the South of the Province, is of the ordinary size, and was used for riding until it struck some one that he was a curiosity. He is very quiet and allowed his fore legs to be lifted without difficulty but on lifting the hind staggered about as if unable or unused to stand in that position

We returned on the following day to make a more detailed examination and hoping to be allowed to take a photograph but found that he had been shipped to be sent to London on board the “Maskelyne” one of Lamport and Holt’s steamers which will sail on the 11^th for Southampton Antwerp and thence to Liverpool and by which this letter will be forwarded. The owner not paying the freight here the animal will be in charge of the Captain and if not claimed at Southampton will be taken on. The Captain—Hairby—will be glad to give any information⁴

Talking over this matter yesterday Mr Grenfell—son of the Admiral—who has an estancia in Entre rios told me that there is a pony there known as the “petizo a cinco patas” which has four additional hoofs on each leg—that he had never particularly examined it but would do so on his return⁵

Hoping that the subject may be of sufficient interest to excuse me for troubling you | I am, my dear Sir | yours truly | John Coghlan

Charles Darwin Esq^r.