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Darwin Correspondence Project

From Arthur Nicols   11 March 1871

The Priory. | Mill Hill. N.W.

March 11th 1871

Dear Sir.

I have to thank you for deeming my communication of the facts relating to Phascolarctus worthy of attention.1 Whatever interest they may have is not impaired by imperfect memory of the circumstances: for I extracted the account sent you from notes made at the time when the facts were observed.

As to the individual brought up by the cat, I shall immediately communicate with the friend at whose house I saw her mothering it, and ascertain every particular: then I shall beg leave to trouble you again.2

I have no doubt you feel, as I have in a limited degree, the importance of being able to place confidence in the powers of observation of a given person— There are so many men whose account of the simplest phenomenon is worthless because they have an imaginative habit of mind, and possess none of the knowledge requisite to guide them in the selection of salient features. As to my friend I have carefully studied the manner in which he is accustomed to bring his mind into relation with any phenomena new to his experience and am convinced of the accuracy of his impressions. I could in fact place almost the same amount of confidence in his relation as if I had observed every detail myself. The evidence transmitted from his mind to mine would have nearly the same force as if it had been taken by my own senses.

I thought at the time that there was something unusual in the young Koala being able to subsist for even a short time on the milk of a genus so far removed as to the structure of the group of organs connected with reproduction. My own invariable failure to rear, on cow’s milk, young Koalas taken from the mother, made this case of successful adoption appear to me the more noteworthy.

I shot one occasion a “scrubb wallaby”3 (female) weight 13 lbs who had a young male in the pouch about the size of a large rat, well covered with hair and unattached. Seeing that the glands were in full lactation I sewed the young one up in the pouch that it might have the benefit of the milk as long as the body kept warm, and took it home, having to row some 30 miles— It was thus some 6 hours without proper nourishment. I ascertained, (for it became quite tame in 24 hours) that it had not yet fed itself, by offering it every variety of its natural food. I determined to rear it if possible by giving cow’s milk in which leaves of different Eucalypti had been macerated, and found that it did not suffer from diarrhœa as all others had done. I succeeded in rearing it to maturity; whether by means of the astringent principle given to the milk or not this one instance cannot determine— I believe that the difficulty of bringing some Australian Animals alive to England might be overcome by mixing with their food a portion of Gum leaves (pounded) after having been prepared by drying them green in the sun.

With many thanks for your courtesy to a stranger. | I am, Dear Sir. | Yours truly | Arthur Nicols.

P.S. If you think it necessary I can easily obtain confirmation from several eye witnesses of the fondness of the Koalas for Tobacco and Rum.

A. Nicols

To | Chas Darwin— Es. F.R.S.


See letter from Arthur Nicols, 7 March 1871 and nn. 1 and 2. CD’s letter to Nicols has not been found.
The scrub wallaby or black striped wallaby is Macropus dorsalis.


His previous account of Phaseolarctus was based on notes made at the time of observation.

His report of the successful adoption of a koala infant by a cat comes from a trustworthy observer.

Letter details

Letter no.
Robert Arthur (Arthur) Nicols
Charles Robert Darwin
Sent from
Mill Hill
Source of text
DAR 172: 56
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7570,” accessed on 15 October 2019,

Also published in The Correspondence of Charles Darwin, vol. 19