Christian Conrad Sprengel. lOO^ 



priately conclude this letter: "Until 1860 and some years afterwards in any cata- 

 logue of old botanical books, the work of Conrad Sprengel, published in 17Q3, 

 'Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen' 

 might be found at the price of about 15 sgr. (15. bd), and I myself bought 

 it there at that price as a curiosity, for the sake of its stränge title. In the 220 th 

 catalogue of Friedlaender (1873) the price of the same book in 3 thlr. 20 sgr. (iis) 

 This rise in the price of Sprengel's book shows ver}^ strikingly the change through 

 vvhich in the meantime it has passed in our appreciation. For only during the 

 last ten years, after it had remained wliolly unnoticed for nearly sevcnty years, 

 the old book has come to be duly valued. It was Charles Darwin, who by his 

 excellent book on Orchids . . . revived the questions treated by Sprengel" {Jenaer 

 Literatur Zeittmg, 1874, article 140.) 



Blumenau, Sa. Catharina, Brazil, December 15, 1883. 



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 Prussia, and I think it 

 would be easy to any one resident in Germ any 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- ^^2) 3-"^ 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 istead of through 

 the stigmatic papillae; and this must have been almost impossible for any one 

 acquainted with Sprengel's excellent account of Canipamila rotundifolia ("Ent- 

 deckte Geheimniss", p. log). 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 Campa- 

 nulacese and Compositae (see Sprengel, pp. log and 370), the pollen-masses of 

 Orchidese and Asclepiadeae being fixed ncar 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, Passi- 

 flora, and Epilobium (Sprengel, pp. 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" nevcr 

 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 tili, as Prof. Möbius justly rcmarks (Nature, vol. xxix. p. 406), "the value of 

 his treatise in its bearing on the theory of selection was first recognised by 

 Charles Darwin." 



Blumenau, Sa. Catharina, Brazil, May 25, 1884. 



