PLANT HYBRIDIZATION BEFORE MENDEL 347 



printing, that I very impatiently wrote to the editor, that in the mean- 

 while the works of Mendel had been printed by Goebel in Flora (1901). 

 Now at length Mendel's works were found worthy of being enrolled in 

 the 'Klassiker der exakten Wissenschaften.' " 



For the younger Tschermak, as he states, it was not easily 

 effected to bring his re-discovery of Mendel, simultaneously made 

 with De Vries and Correns, into general recognition. Thus, in 

 the early years after the re-discovery of the Mendel ian Laws, in 

 references to the discoveries the mention of his name was omitted 

 altogether, as in the "Lehrbuch" of Strasburger and Wettstein. 

 Nevertheless, this oversight was soon made good. Continuing, he 

 states : 



"The practical significance of Mendelism for plant and animal breed- 

 ing was first immediately recognized by myself, and always emphasized ; 

 as also the great part of my publications even today, with theoretical 

 conclusions, always place the practical side in the foreground. Through 

 my visit in the year 1901 at Svalof, the method of breeding hitherto 

 obtaining there was directed to quite new, modern, 'Mendelian' lines, 

 which is now recognized ungrudgingly in Sweden by Nilsson-Ehle." 



The preliminary paper of von Tschermak's, referred to in the 

 letter above, contributed to the Berichte der deutschen botanischen 

 Gesellschaft, and entitled "tJber kiinstliche Kreuzung bei Pisum 

 sativum^'' was printed as Contribution 26, pp. 232-9 of volume 

 18, and received by that journal for publication on June 2, 1900. 

 This paper, although in a sense an abstract of the much fuller con- 

 tribution to the Zeitschrift fiir das landwirtschaftliche Versuchs- 

 wesen in Oesterreich, Heft 5, 19CO, is nevertheless of special in- 

 terest, since it renders the first account of the author's experi- 

 ments appearing in the issues of a botanical journal. 



The author states : 



"Prompted by the experiments of Darwin on the effects of cross- and 

 self-fertilization in the plant kingdom, I began in the year 1898 to 

 institute crossing experiments with Pisum sativum, because especially 

 the cases of exceptions from the principle generally expressed, concern- 

 ing the advantageous effect of the crossing of different individuals and 

 different varieties in contrast to self-fertilization, interested me — a group 

 to which Pisum sativuvi also belongs." (3a, p. 232.) 



The author then gives a brief summary of Darwin's experi- 

 ments, and states that, in view of the small amount of the lat- 

 ter's experimental material, it appeared to be called for, espe- 

 cially since Darwin did not emasculate the flowers, to repeat these 



