From Alfred Newton   29 May 1871

The reference is to Adams 1870. CD inserted the following note in Descent 2d ed., p. 409 n. 9: I am indebted to Professor Newton for the following passage from Mr Adam’s Travels of a Naturalist, 1870, p. 278. Speaking of Japanese nut-hatches in confinement he says: ‘Instead of the more yielding fruit of the yew, which is the usual food of the nut-hatch in Japan, at one time I substituted hard hazelnuts. As the bird was unable to crack them, he placed them one by one in his water-glass, evidently with the notion that they would in time become softer—an interesting proof of intelligence on the part of these birds.’

Francis Darwin had completed his examinations for a degree in natural sciences at Cambridge, and had begun his medical studies at St George’s Hospital, London (ODNB, letter to Francis Darwin, 25 March [1871]); however, he evidently needed to return to Cambridge to fulfil the residency requirements for a degree (see Cambridge University calendar 1871, pp. 4–5).