The role of Liberty Hyde Bailey and Hugo de Vries in the rediscovery of Mendelism

1. The almost simultaneous and overlapping discoveries of Mendel's forgotten work by Hugo de Vries, Carl Correns, and Erik von Tschermak gave rise to an intense rivalry, some jealousy, and more than a little illfeeling. De Vries, the first to announce the discovery, has been subjected to the charge that he wished to conceal his discovery and to obtain for himself the credit for having discovered what we now call Mendelism. This charge involves the statement that de Vries gave credit to Mendel only after he had found that others had also read Mendel's papers. The evidence on which this charge is based is sketchy, and we can now show that at least that portion of it that is based on supposed alteration in the proof of de Vries' paper in the Berichte is without foundation. Unfortunately, de Vries gave three different accounts of how he was led to Mendel's work. Two of these involve Liberty Hyde Bailey. 2. Bailey had listed Mendel's papers in a bibliography that he published in 1892 in The Rural Library. Bailey did not include this bibliography in the first edition (1895) of Plant Breeding or in its reprinting in 1896 and 1897. He did include the bibliography in the second edition (1902), but this was after de Vries and others had called attention to Mendel. In 1899, both Bailey and de Vries gave papers at the Hybrid Conference held at Chiswick, England, but we have no record of their having discussed Mendel. What evidence we have indicates that, at this time, neither of them had read Mendel's papers. 3. De Vries wrote to Bailey that it was Bailey's listing of Mendel in the bibliography published in The Rural Library that led to his discovery of Mendel. Later, de Vries wrote to H. F. Roberts that he had first found a reference to Mendel in Bailey's Plant Breeding of 1895, where the bibliographic reference to Mendel's papers was not published. Finally, de Vries told Th. J. Stomps, who succeeded him at the University of Amsterdam, that he had first learned of Mendel early in 1900 from a reprint of Mendel's paper sent him by his friend Professor M. W. Beyerinck. Our present evidence favors Stomp's account as it shows that de Vries had not read Mendel's papers in 1899 but had early in 1900. 4. Attempts to pinpoint de Vries' discovery of Mendel are aided in part, and in part confused, by the fact that he published five relevant papers in 1900. These papers were in press simultaneously, and some of them were altered in proof. Further confusion is due to the fact that at least three of them were published in the reverse order of their acceptance for publication. Unfortunately we do not have the crucial dates for all of the papers. a. J. Roy. Hort. Soc. 24: 69–75. A definitely pre-Mendelian paper given on 11 July 1899, and published in 1900 (possibly in April). The evidence for an alteration in proof after de Vries had read Mendel is shown by the fact that de Vries described a ratio of 99 to 54 as a 3 to 1 ratio. b. Rev. gen. botan. 12: 129–137. A Mendelian paper, giving the 3 to 1 ratio in the F2 generation of a cross between starchy and sugary corn. The paper is not dated by de Vries but it was published in the volume, 128 pages ahead of a paper de Vries dated 19 March. In a footnote, de Vries cites a paper by Correns that was published on 25 January, so we can tell that it was written or corrected in proof after this date. Here Correns showed de Vries that he had already read Mendel's paper. Any attempt by de Vries to ignore Mendel or get credit for Mendelism after 25 January would have been senseless. This date was nearly two months before de Vries' Berichte paper was submitted for publication. c. Ber. deut. botan. Ges. 18: 83–90. Accepted for publication 14 march, published 25 April. This paper gives Mendel full credit and stimulated the publications of Correns and von Tschermak. As de Vries was aware that Correns already knew of Mendel when the paper was first submitted, there was no occasion to alter it in proof. d. Rev. gen. botan. 12: 257–271. Dated by de Vries 19 March, but the proof was read after June. De Vries cites von Tschermak's paper in the Berichte that was published in June. The Revue paper is a Mendelian paper, and Mendel is cited on the last page. e. C. R. Acad. Sci. (Paris) 130: 845–847. Accepted for publication 26 March 1900. Reprint received by Correns 21 April. Mendel is not mentioned but de Vries' use of terms told Correns that de Vries had read Mendel's paper. First of the papers to be published, it caused Correns to assume that de Vries wanted the credit that was due Mendel. 5. The three discoverers of Mendel did not form a mutual admiration society.