The year is conjectured from the relationship between this letter and the letter to Hugh Falconer [December? 1844] (see n. 2, below). A copy of this letter in DAR 144: 19 was published in Correspondence vol. 6 with the date 8 March [1857]. The original letter later appeared in a Raab Collection catalogue. There are no significant alterations to the text but the footnotes have been rewritten.

CD’s notes have not been identified. Falconer had travelled in Tibet in 1837 and 1838, and lent CD his manuscript account of the expedition (see Correspondence vol. 24, Supplement, letter to Hugh Falconer, [December? 1844] and n. 2). He later published the observation that the Tibet mastiff and goat lost their fine wool when brought down from the Himalaya to Kashmir (Falconer 1863, p. 113); CD cited this article as support for his claim that climate influenced the hairy covering of animals (Variation 2: 278).

CD had a conversation with Falconer in late 1844 (see Correspondence vol. 24, Supplement, letter to Hugh Falconer, [December? 1844]). See also Correspondence vol. 3, letter to Adolf von Morlot, 28 November [1844] and n. 6. Falconer was an employee of the East India Company but had returned to England in 1842 on sick leave; he was obliged to return to India on 20 December 1847 in order to fulfil the conditions for his pension (see C. Murchison ed. 1868, 1: xxxix).