Bailey had sent CD specimens of Bouvardia leiantha (see letter from W. W. Bailey, [November 1877] and n. 3). In Forms of flowers 2d ed., p. vii, CD noted that the specimens sent by Bailey were clearly heterostyled, but that no difference could be detected in the size of the pollen-grains.
The New York Public Library. Astor, Lenox, and Tilden Foundations. Manuscripts and Archives Division. (Alfred Williams Anthony collection: box 7, folder 10)