Christian Conrad Sprengel

Abstract

WILL you allow me a short reply to Prof. Hagen's letter published in NATURE (vol. xxix. p. 572)? It is evident that Prof. Hagen's statements are very far from proving what he asserted in his former letter, viz. that between 1830 and 1840 Sprengel's discoveries were known to every student in Prusia, and I think it would be easy to any one resident in Germany to prove the contrary by simply confronting what the manuals of botany published at that time say about the fertilisation of flowers. Thus, as I learn from Delpino's “Ulteriori Osservazioni” (p. 88), Link (“Elem. Philos. Bot.,” ii. 1837, p. 222) and Treviranus (“Physiol. der Gew.,” ii. 1838, p. 343), both of whom, according to Hagen, were entirely acquainted with Sprengel's discoveries, adopt Cassini's erroneous view of the fertilisation of Campanula being effected through the collecting-hairs of the style instead of through the stigmatic papillæ; and this must have been almost impossible for any one acquainted with Sprengel's excellent account of Campanula rotundifolia (“Entdeckte Geheimniss,” p. 109). What Prof. Kunth, in his lectures at the Berlin University, taught about the fertilisation of flowers may be seen in his “Lehrbuch der Botanik” (1847, p. 422). Almost every line contains errors splendidly and convincingly refuted by Sprengel. Thus he considers as contrivances serving to aid the self-fertilisation of the flowers the collecting-hairs on the style of Campanulaceæ and Compositæ (see Sprengel, pp. 109 and 370), the pollen-masses of Orchideæ and Asclepiadeæ being fixed near the stigma (Sprengel, pp. 401 and 139), the movements of the stamens of Parnassia, Ruta, and Saxifraga (Sprengel, pp. 166, 236, and 242), as well as the movements of the stigmas of Nigella, Passiflora, and Epilobium (Sprengel, p. 280, 160, and 224). I do not know how to reconcile these errors with Prof. Hagen's statement that Kunth was “beyond doubt acquainted with the facts” discovered by Sprengel. He “beyond doubt” never read Sprengel's book, and I can explain those numerous and crass errors of one of the most celebrated botanists only by the assumption that at that time Sprengel had fallen into almost complete oblivion among German botanists, and remained so till, as Prof. Möbius justly remarks (NATURE, vol. xxix. p. 406), “the value of his treatise in its bearing on the theory of selection was first recognised by Charles Darwin.”