The date range is established by the period in which CD worked on movement in cotyledons (see Correspondence vol. 25, letter to R. I. Lynch, 14 September 1877).
CD received a specimen of Haematoxylon campechianum (a synonym of Haematoxylum campechianum, logwood) from Kew in 1877 (see Correspondence vol. 25, letter from W. T. Thiselton-Dyer, 25 July 1877). He discussed the nocturnal movement of its leaves in Movement in plants, pp. 368–9; however, he credited Lynch with observations of cotyledons (ibid., p. 300). On the sleep of cotyledons in Cassia, see Correspondence vol. 25, letter to R. I. Lynch, 14 September 1877).