152 



The Journal of Heredity 



which fact man had depended for the 

 selection of "superior" types of plants, 

 and hence for the "improvement" of 

 plant races. 



But, unfortunately, these discoveries 

 and disclosures of Sprengel's awakened 

 Httle interest at the time. Like Camera- 

 rius and Koelreuter, Sprengel, in turn, 

 was a stone that the builders rejected. 

 Biologists of his day believed in the 

 dogma of the fixity of species, to which 

 Koelreuter's experiments in the making 

 of hybrids, and Sprengel's epoch-making 

 discoveries regarding cross-polHnation 

 by means of insects, were directly con- 

 tradictory. 



THE OPENING OF A NEW ERA 



The beginning of the nineteenth 

 century marks the beginning of a new 

 era in plant breeding, initiated by the 

 work of the English breeders and 

 naturalists, Andrew Knight and William 

 Herbert, and of the celebrated German 

 hybridizer, Carl Friedrich von Gartner. 

 Through the extensive and intelligent 

 experimentation of these men, the fact 

 of sexuality in plants was emphasized, 

 and the inauguration of the era of 

 practical plant breeding was effected. 

 Although the scientific world of today 

 traces a continuity of thought and 

 investigation from Gartner back to 

 Camerarius, the fact must not be lost 

 sight of, that each of the three great 

 investigators who laid the foundations 

 of plant breeding — Camerarius, Koel- 

 reuter, and Sprengel — was completely 

 ignored by, and practically unknown to, 

 the biological science of his own time. 

 The torch of discovery was not passed 

 from hand to hand, but was lighted, as it 

 were, three separate times. 



Two human generations elapsed from 

 the work of Camerarius to that of 

 Koelreuter, and one generation from 

 Koelreuter to Sprengel. It is more than 

 another generation from Sprengel's pub- 

 lication to the time of the best work of 

 Herbert (1837). It is a third of a 

 generation more to the appearance of 



Gartner's memoir (1849), and about 

 half of another generation more to the 

 appearance of Mendel's epoch-making 

 and now celebrated papers (1866), and 

 more than another generation again to 

 the date of the final rediscovery of 

 Mendel's work (1900), the beginning of 

 the Mendelian or scientific age of plant 

 breeding, which ushered in the era of the 

 development of what we call the science 

 of "genetics." 



BIBLIOGRAPHY 



Literature pertaining to sexuality in plants, 



and to hybridization, from Koelreuter 



(1760), to Sprengel (1793). 



1. Bradley, Richard, New Improvements of 

 Planting and Gardening, Sixth Ed. London, 

 1719. 



2. Gartner, Carl Friedrich von, Versuche 

 and Beobachtungen uber die Bastarderzeugung 

 im Pflanzenreich, Stuttgart, 1849. 



3. Gleditsch, Johann Gottlieb, (a) Essai 

 d'une fecondation artificielle, fait sur I'espece 

 de palmier qu'on nomme Palma dactylifera 

 folio flabiUiforme. Histoire de I'Academie 

 royale des sciences et des belles lettres de Berlin, 

 1749. Pp. 103-108, 1751. {b) Relation de la 

 fecondation artificielle d'un palmier femelle, 

 reiteree pour la troisieme fois, et avec un plein 

 succes, dans le Jardin botanique, de Berlin. 

 Histoire de I'Academie rovale des sciences et 

 des belles lettres de Berlin, 1767, pp. 3-19, 1769. 



4. Koelreuter, Joseph Gottlieb, (c) Vor- 

 laufige Nachricht von einigen, das Geschlecht 

 der Pflanzen betrefifenden Versuchen und 

 Beobachtungen, nebst Fortsetzungen 1, 2, 

 and 3 (1761-1766); edited by W. Pfeffer, as 

 No. 41 in Ostwald's "Klassiker der Exakten 

 Wissenschaften." Leipzig, 1893. ib) Histoire 

 der Versuche iiber das Geschlecht der Pflanzen, 

 in Miken's "Opuscula Botanici Argumenti." 



5. Logan, James, (a) Experimenta et melete- 

 mata de plantarum generatione. Lugduni 

 Batavorum, (Leiden), 1739. {b) Experiments 

 and considerations on the generation of plants. 

 Second edition of above. English and Latin on 

 opposite pages, and with both English and 

 Latin title page. London, 1747. 



6. Miller, Philip, Gardener's Dictionary, 

 Extract quoted, found in the following editions. 

 1st Ed. 1731, 6th (folio), 1752, 7th, 1759. 

 Extract in text taken from edition of 1759, 

 unpaged, in article entitled "Generation" 

 toward the end of the volume. 



7. Sprengel, Christian Konrad, Das Ent- 

 deckte Geheimniss der Natur, im Bau und in 

 der Befruchtung der Blumen, 1793. Ed. by 

 Paul Knuth. In Ostwald's Klassiker der 

 Exakten Wissenschaften, No. 48. 4 vols., 

 Leipzig, 1894. 



