From W. E. Darwin   6 May 1864

The sketches are reproduced at 50 per cent of their original size. With his letter to William of 3 May [1864], CD sent long-styled and short-styled flowers of Pulmonaria angustifolia, asking William to sketch the anthers so that he could compare the size in both forms. William included additional sketches of anthers with his letter of 12 May [1864]; he sent sketches of anthers in the bud with his letters of 18 May [1864] and 24 May 1864.

CD had grown curious about the shape of the stigma in the two forms of the dimorphic Pulmonaria angustifolia (see letter from W. E. Darwin, 14 April [1864] and n. 9, and letter to W. E. Darwin, [after 14 April – 5 May 1864]). William mentioned later that he thought all the stigmas were ‘more or less bilobed’ (see letter from W. E. Darwin, 12 May [1864], and n. 7).