Note 34 — Zur Biologie der phanerogamischen Süsswasserflora.
Reading edition
William Trelease, On the Structures which favor Cross-fertilizization in several Plants. Proceed. of the Bost. Soc. of Nat. Hist. Vol. XXI, 1882, March 15, p. 410–440 (m. 52 Fig. auf 3 Taf.).