Journal of the History of Biology

, Volume 5, Issue 2, pp 327–353 | Cite as

The reception of Eduard Buchner's discovery of cell-free fermentation

  • Robert E. Kohler
Article

Conclusions

What general conclusions can be drawn about the reception of zymase, its relation to the larger shift from a protoplasm to an enzyme theory of life, and its status as a social phenomenon?

The most striking and to me unexpected pattern is the close correlation between attitude toward zymase and professional background. The disbelief of the fermentation technologists, Will, Delbrück, Wehmer, and even Stavenhagen, was as sharp and unanimous as the enthusiasm of the immunologists and enzymologists, Duclaux, Roux, Fernback, and Bertrand, and of Pfeffer, the experimental plant physiologist. Other skeptics—Voit, Kupffer, and Fischer—were conservatives in traditional fields. In all these cases it seems clear that professional commitments and outlook profoundly influenced the reception of zymase.

In some cases there is a correlation with a specific earlier statement favoring the protoplasm theory or predicting a fermentation enzyme. Reynolds Green is a striking case of both. In 1893 he stated his belief that life processes in higher plants and fungi were identical, both being mediated by protoplasm.109 Thus he claimed that digestion was not carried out by enzymes, as in higher animals, but by the whole protoplasm, and so too fermentation in yeast: “All the metabolic processes must be carried out in the unicellular organism in the same mass of protoplasm.”110 But Green also insisted that there was no essential difference between “organized” and “unorganized ferments”; enzymes were simply more highly differentiated and specialized forms of primitive protoplasm. He spoke of “the alcoholic ferment” (that is, enzyme), and of intracellular enzymes—very advanced beliefs for 1893. Thus it is understandable why Green saw no reason to doubt his first negative results with yeast juice, and rushed into print. But it is also understandable that he persisted and soon became an outspoken advocate of Buchner's view; like Wroblewski and Pfeffer, he had already accepted the idea of an intracellular fermentation enzyme.

The physiological chemists also fit the pattern in a special way. Physiological chemistry is generally regarded as the source of biochemistry; indeed, many early biochemists were trained in physiological chemistry, and imbibed there a progressive interest in enzymes and metabolism. It is not surprising, therefore, that on the whole Neumeister, Madfadyen, Wroblewski, and Loew accepted cell-free fermentation. But what is surprising, and significant, is the diversity of opinion in this group, from Abeles' living protoplasm to Wroblewski's organized array of active proteins. The feelings of the physiological chemists were mixed, and there was enough of the old protoplasm view in Macfadyen's and even Wroblewski's views to allow Buchner to see them as attacks on zymase. The ideas of physiological chemistry were also changing; the idea of protoplasm was already adjusting to the new interest in enzymes in the early 1890's. But in contrast to immunochemistry, the change in physiological chemistry was gradual, uneven, undramatic, and relatively invisible. For the new biochemistry, the tradition of physiological chemistry was the source of traditional conservatism as well as of new ideas of enzymes.

In general, then, I claim that it was not experimental facts that determined attitudes toward zymase so much as previous commitments, experience, and expectations. Initially, at least, zymase was less a determinant of opinion than a touchstone of pre-existing opinion. Like a prism, it revealed the spectrum of existing attitudes toward vital phenomena.

Also relevant here is the fact that the experimental evidence was entirely ambiguous; the interpretation of Buchner's experiments with antiseptics or dried yeast depended entirely on how far one was willing to stretch the scope of the terms “protoplasm” and “enzyme”. Likewise, how important one judged the instability of zymase to be, or the low level of in vitro activity, depended largely on one's point of view. There was no crucial experiment, no certain proof. Logically zymase could be regarded as protoplasm. A. Fischer did so in 1900;111 Macfadyen was still wavering in 1907;112 and Beijerinck was holding out as late as 1916.113 There were undoubtedly others. Besides the special case of Reynolds Green and the technologists, there are no recorded cases of conversion.

But if there was no evidence to convert a dedicated protoplasmist, there was plenty to encourage a dedicated belief in the enzyme theory, and that, I believe, is precisely what happened. The arguments of Buchner et al in support of zymase had the greatest effect not on the protoplasmists but on those who were already predisposed toward the biochemical view. The zymase debate enabled the emerging group of biochemists to recognizethemselves as a group with a community of out-look and objectives; it brought the issue of protoplasm vs. enzyme into the open and gave it a specific and concrete issue on which to turn. The debate sharpened the biochemists' awareness that their point of view was becoming the new mainstream of biochemical thought.

All this of course had an important secondary effect on those who opposed the new view, or who were not immediately concerned with it. After the zymase debate, it would have been almost impossible to ignore the new ideas; the dramatic and wide publicity the debate enjoyed would have made it difficult not to take sides. Buchner's successful defense of zymase itself became an important influence on opinion; the new movement had to be looked at with respect. But the primary effect of the debate, I assert, was on those who were already inclined to the new view. The outcome was not a mass conversion of individuals, nor the ejection of one idea by another. The sides probably did not change much; the real change was in the way each side regarded itself and its place in history. The zymase debate may perhaps best be regarded as a process of selection. Buchner's party became aware of itself as the new progressive point of view, while those holding the traditional view could no longer expound it publicly without appearing obstinate or old-fashioned. Thus the way was clear for the gradually wider establishment of the new ideas, especially among the new generation of biochemists. In this specific sense, the acceptance of zymase was a social phenomenon.

This way of looking at the zymase debate also illuminates its coincidence with the emergence of biochemistry as a profession. The new professional trappings and organizations were the social manifestation of the new self-awareness gained from the zymase controversy. One of the most important effects on those disposed toward the new view was the awareness of an intellectual community and of the need to give that community social forms. The almost mythical importance of Buchner's “victory” over the old protoplasm theory that later became current is readily understandable. It was a useful ideology for a group anxious to assert the novelty of their approach, a novelty which they in fact felt quite keenly.

But if the primary effect of the zymase controversy was on those predisposed to accept zymase, then obviously the success of zymase depended on the fact that change had already begun to occur. Indeed, one of the most striking, and again unexpected, results of this study is the extent to which the importance of enzymes was already recognized in the early 1890's. The new immunology clearly pointed the way. Macfadyen and Hans Buchner were looking for active proteins inside the cell in 1893. Reynolds Green, Wroblewski, and Pfeffer had all anticipated the discovery of a fermentation enzyme. Other discoveries in enzymology in the 1890's pointed the same way.114 Moreover, it is clear from this study that the old protoplams theory was adapting to the new discoveries concerning the importance of enzymes. The sidechains of the old protoplasm molecule were simply reinterpreted as enzymes, as in Wroblewski's theory, for example, or in Paul Ehrlich's extremely influential “sidechain theory” of antibody formation (1897). Despite the later views of Hopkins et al., the old protoplasm and the new enzyme theories were not irreconcilable; a continuity of development had already begun when zymase came so dramatically on the scene. Buchner himself observed that the difference between the two views had become largely verbal; in retrospect we might say, not verbal, but social and historical. The gap between the continuous change in ideas and the contemporary feeling of sharply discontnuous change is a measure of the elusive but real social and historical implications of the zymase debate, of the demise of an old establishment, and the emergence of a new.

In retrospect, then, it is clear that a trend was already under way in various quarters when zymase appeared. But it was still a collection of isolated and dispersed events. The zymase controversy made the trend visible and gave it a dramatic unity. The debate influenced those who had already begun to change. It was so effective because things had begun to change and because it coincided with the direction of that trend.

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References

  1. 1.
    R. E.Kohler, “The Background to Eduard Buchner's Discovery of Cell-free Fermentation,” J. Hist. Biol., 4 (1971), 35–61. Journal of the History of Biology, vol. 5, no. 2 (Fall 1972), pp. 327–353.Google Scholar
  2. 2.
    R. E. Kohler, “The Enzyme Theory and the Origins of Biochemistry.” (Isis, in press).Google Scholar
  3. 3.
  4. 4.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 299–302, 321–322.Google Scholar
  5. 5.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 322.Google Scholar
  6. 6.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 301.Google Scholar
  7. 7.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 300.Google Scholar
  8. 8.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 321.Google Scholar
  9. 9.
    H.Buchner, “Die Bedeutung der activen löslichen Zellprodukte für den Chemismus der Zelle,” Münch. med. Wochens., 44 (1897), 322.Google Scholar
  10. 10.
  11. 11.
    Anon, “Zum 70 Geburtstag Carl v. Kupffer's,” Münch. med. Wochens., 46 (1899), 1539–1541.Google Scholar
  12. 12.
    H.Buchner, Münch. med. Wochens., 44 (1897), 301.Google Scholar
  13. 13.
    H.Buchner, Münch. med. Wochens., 44 (1897), 322.Google Scholar
  14. 14.
    E.Buchner, “Alkoholische Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 30 (1897), 117–124.Google Scholar
  15. 15.
    E.Buchner, “Alkoholische Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 30 (1897), 120.Google Scholar
  16. 16.
    E.Buchner, “Alkoholische Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 30 (1897), 121.Google Scholar
  17. 17.
    H.Buchner, Münch. med. Wochens., 44 (1897), 302.Google Scholar
  18. 18.
    A similar mixture of old and new is also evident in the precedents Buchner cited for his view. Miguel regarded the new enzyme, urease, as a part of the protoplasm acting outside the cell, while Emil Fischer concluded that a diastatic enzyme of Candida monilla that was inactive in crushed cells remained attached to the intracellular protoplasm.Google Scholar
  19. 19.
    E.Buchner “Alkoholische Gährung ohne Hefezellen II,” Ber. deut. chem. Ges., 30 (1897), 1110–1113.Google Scholar
  20. 20.
    E.Buchner “Alkoholische Gährung ohne Hefezellen II,” Ber. deut. chem. Ges., 30 (1897), 1112.Google Scholar
  21. 21.
    E.Buchner and R.Rapp, “Alkoholische Gährung ohne Hefezellen III,” Ber. deut. chem. Ges., 30 (1897), 2668–2678.Google Scholar
  22. 22.
    H.Will, “Alkoholische Gährung ohne Hefezellen,” Wochens. Brauerei, 29 (July 16, 1897), 363–364.Google Scholar
  23. 23.
    F.Haydruck, “Max Delbrück,” Ber. deut. chem. Ges., 53A (1920), 47–62.Google Scholar
  24. 24.
    See Wochens. Brauerei, 29 (1897), 364.Google Scholar
  25. 25.
    J. Soc. Chem. Ind. 1897, 750–751.Google Scholar
  26. 26.
    E.Buchner and R.Rapp, “Alkoholische Gährung ohne Hefezellen IV,” Ber. deut. chem. Ges., 31 (1898), 209–217.Google Scholar
  27. 27.
    J.Reynolds Green, “The Supposed Alcoholic Enzyme in Yeast,” Ann. Bot., 11 (1897), 555–562.Google Scholar
  28. 28.
    S. H. V., “Joseph Reynolds Green,” Proc. Roy. Soc., 88B (1915), xxxvi-xxxviii.Google Scholar
  29. 29.
    A.Stavenhagen, “Zur Kenntniss der Gährungsercheinungen,” Ber. deut. chem. Ges., 30 (1897), 2422–2423.Google Scholar
  30. 30.
    H.Wöbling, “A. Stavenhagen,” Ber. deut. chem. Ges, 64A (1931), 10–12.Google Scholar
  31. 31.
    A.Stavenhagen, “Zur Kenntniss der Gährungserscheinungen,” Ber. deut. chem. Ges., 30 (1897), 2963, and E. Buchner and R. Rapp, ibid., 31 (1898), 210–212.Google Scholar
  32. 32.
    E. Buchner and R. Rapp (n. 31 above), p. 211.Google Scholar
  33. 33.
    A. Fischer, Vorlesungen über Bacterien (Jena, 1897), p. 172.Google Scholar
  34. 34.
    M.Biejerinck, “Weitere Beobachtungen über die Octosporushefe,” Centralb. Bact. (pt. II), 3 (1897), 454–455.Google Scholar
  35. 35.
    W. B., “M. Beijerinck,” Proc. Roy. Soc., 109B (1932), i-iii.Google Scholar
  36. 36.
    J.Behrens, “Alfred Fischer,” Ber. deut. bot. Ges., 31 (1913), pp. (m)-(n7).Google Scholar
  37. 37.
    A. Fischer, Färbung und Bau des Protoplasmas (Jena, 1899).Google Scholar
  38. 38.
    C.Wehmer, “Gährung' ohne Hefezellen,” Bot. Z., 65 (1898), 57–61.Google Scholar
  39. 39.
    C.Wehmer, “Fortschritte in der Chemie der Gährung,” Centralb. Bakt. (pt. II), 3 (1897), 528–529.Google Scholar
  40. 40.
    C.Wehmer, Bot. Z., 65 (1898), 61.Google Scholar
  41. 41.
    Anon, “Carl Wehmer,” Z. angew. Chem., 48 (1935), 132.Google Scholar
  42. 42.
    C. J.Martin and H. G.Chapman, “An Endeavour to Procure an Alcoholic Ferment from Yeast Cells,” J. Physiol., 23 (1898), ii-iv. (Proc. Physiol. Soc. 11 June 1898)Google Scholar
  43. 43.
    E.Buchner, “Ueber zellenfreie Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 31 (1898), 568–574.Google Scholar
  44. 44.
    H.Lange, “Beitrag zur alkoholischen Gährung ohne Hefezellen,” Wochens. Brauerei, 15 (1898), 377–378.Google Scholar
  45. 45.
    J. R. Greene, “The Alcohol Producing Enzyme of Yeast,” Rep. Brit. Assn. 1898, p. 1046. Ann. Bot., 12 (1898), 491–497.Google Scholar
  46. 46.
    J. R. Greene, The Soluble Ferments (London, 1899).Google Scholar
  47. 47.
    F. Ahrens, “Ein Beitrag zur Zellenfreien Gährung,” Z. angew. Chem. 1900, 483–486.Google Scholar
  48. 48.
    Ibid., 483.Google Scholar
  49. 49.
    See Wochens. Brauerei, 16 (1898), 485–488.Google Scholar
  50. 50.
    G.Heinzelmann, “Die Entwicklung und der Stand unserer heutigen Kenntnisse über die alkoholische Gärung,” Chem. Z., 1 (1901–02), 158–160, 181–183.Google Scholar
  51. 51.
    E.Duclaux, Ann. Inst. Pasteur, 11 (1897), 287.Google Scholar
  52. 52.
    E.Duclaux, “Sur l'action des diastases,” Ann. Inst. Pasteur, 11, 793–800 (1897).Google Scholar
  53. 53.
    E.Duclaux, “Sur l'action des diastases,” Ann. Inst. Pasteur, 11, 794 (1897).Google Scholar
  54. 54.
    A.Fernbach, Bull. Soc. Chim. Fr., 18 (1897), 814–815.Google Scholar
  55. 55.
    G.Bertrand, “Le Mechanisme de la fermentation alcoholique et les expériences de Buchner,” Rev. gen. Sci., 9 (1898), 907–910.Google Scholar
  56. 56.
    G.Bertrand, “Le Mechanisme de la fermentation alcoholique et les expériences de Buchner,” Rev. gen. Sci., 9 (1898), 910.Google Scholar
  57. 57.
    E. Roux, La Fermentation alcoholique et l'evolution de la microbie (Lille, 1898). Abstracted in Schweiz. Wochens. Chem. Pharm., 37 (1899), 54–57. It is a pleasure to thank Miss Denise Wrotnowska for sending me a xerox copy of this pamphlet.Google Scholar
  58. 58.
    Anon, “Sur la vie et les travaux d'Emile Duclaux,” Ann. Inst. Pasteur, 18 (1904), 337–362.Google Scholar
  59. 59.
    W. Pfeffer, Pflanzenphysiologie, 2nd ed., (Leipzig, 1897), I, 503, 559.Google Scholar
  60. 60.
    Verh. 71 Versam. Ges. deut. Naturf. u. Aertze 1899 (pt. II, first half), Naturwiss Abt., pp. 210–211.Google Scholar
  61. 61.
    E.Buchner, “Bemerkungen zur Arbeit von A. Macfayden,” Ber. deut. chem. Ges., 33 (1900), 3311–3315.Google Scholar
  62. 62.
    H.Fittig, “Wilhelm Pfeffer,” Ber. deut. bot. Ges., 38 (1920), (30)-(63).Google Scholar
  63. 63.
    J. Loeb, The Dynamics of Living Matter (New York, 1906).Google Scholar
  64. 64.
    R.Neumeister, “Bemerkungen zu E. Buchner's Mittheilung über Zymase,” Ber. deut. chem. Ges., 30 (1897), 2963–2966.Google Scholar
  65. 65.
    M.Matthew, “Richard Neumeister,” Münch. med. Wochens., 53 (1906), 140–143.Google Scholar
  66. 66.
    R. Neumeister, Lehrbuch der Physiologischen Chemie (Jena, 1893), 2nd ed., 1897.Google Scholar
  67. 67.
    R. Neumeister, Betrachtungen über das Wesen der Lebensercheinungen, Beitrag zum Begriff des Protoplasmas (Jena, 1903).Google Scholar
  68. 68.
    Ibid., p. 31.Google Scholar
  69. 69.
    Ibid., p. 63.Google Scholar
  70. 70.
    E.Buchner and R.Rapp, “Alkoholische Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 31 (1898), 209–217.Google Scholar
  71. 71.
    H.Abeles, “Zur Frage der alkoholischen Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 32 (1899), 2261–2267.Google Scholar
  72. 72.
    H.Abeles, “Zur Frage der alkoholischen Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 32 (1899), 2267.Google Scholar
  73. 73.
    E.Buchner and R.Rapp, “Zur Frage der alkoholischen Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 32 (1899), 127–137.Google Scholar
  74. 74.
    E.Buchner and R.Rapp, “Zur Frage der alkoholischen Gährung ohne Hefezellen,” Ber. deut. chem. Ges., 32 (1899), 136.Google Scholar
  75. 75.
    A.Macfadyen, G. H.Morris, and S.Rowland, “On Expressed Yeast-Cell Plasma (Buchner's Zymase),” Proc. Roy. Soc., 67B (1900), 250–266.Google Scholar
  76. 76.
    A.Macfadyen, G. H.Morris, and S.Rowland, “On Expressed Yeast-Cell Plasma (Buchner's Zymase)”, Proc. Roy. Soc., 67B (1900), 264–265.Google Scholar
  77. 77.
    Anon, “Allen Macfadyen,” J. Hygiene, 7 (1907), 319–322. Lancet (1907), 1, 696–697. H. chick, M. Hume, and M. Macfarlane, War on Disease: A History of the Lister Institute (London, 1971).Google Scholar
  78. 78.
    R. E. Kohler, “The Background to Arthur Harden's Discovery of Coenzyme,” Bull. Hist. Med. (in press).Google Scholar
  79. 79.
    J. R.Green, “Buchner's Zymase,” Nature, 63 (1900), 106.Google Scholar
  80. 80.
    A.Wroblewski, “Ueber die chemische Beschaffenheit der Diastase,” Z. physiol. Chem., 24 (1897), 173–223. See pp. 178–180.Google Scholar
  81. 81.
    A.Wroblewski, “Gährung ohne Hefezellen”, Centralb. Physiol., 12 (1898), 698.Google Scholar
  82. 82.
    A.Wroblewski, Z. physiol. Chem., 24 (1897), 219.Google Scholar
  83. 83.
    E.Buchner and R.Rapp, “Alkoholische Gährung ohne Hefezellen VIII,” Ber. deut. chem. Ges., 32 (1899), 127–128.Google Scholar
  84. 84.
    A.Wroblewski, “Ueber der Buchner'schen Hefepressaft,” Centralb. Physiol., 13 (1899), 284–298.Google Scholar
  85. 85.
    A.Wroblewski, “Ueber den Buchner'schen Hefepressaft,” J. prakt. Chem., 64 (1901), 1–70.Google Scholar
  86. 86.
    E.Buchner and A.Spitta, “Zymasebildung in der Hefe,” Ber. deut. chem. Ges., 35 (1902), 1703–1706.Google Scholar
  87. 87.
    A.Wroblewski, J. prakt. Chem., 64 (1901), 57.Google Scholar
  88. 88.
    A.Wroblewski, J. prakt. Chem., 64 (1901), 65–66.Google Scholar
  89. 89.
    A.Wroblewski, J. prakt. Chem., 64 (1901), 24–25.Google Scholar
  90. 90.
    F. Hofmeister, Die chemische Organization der Zelle (Braunschweig, 1901).Google Scholar
  91. 91.
    A.Wroblewski, “Ueber die lösliche Stärke,” Ber. deut. chem. Ges., 30 (1897), 2108–2110.Google Scholar
  92. 92.
    O.Loew, “On Buchner's Zymase,” Science, 10 (1899), 955–961. See esp. p. 961.Google Scholar
  93. 93.
    See M.Klinkowski, “Oscar Loew,” Ber. deut. chem. Ges., 74A (1941), 115–136. O. Loew, The Energy of Living Protoplasm (London, 1896).Google Scholar
  94. 94.
    E. Buchner, “Demonstration der Zymasegährung,” (above, n. 60), pp. 210–211.Google Scholar
  95. 95.
    Ibid., p. 210.Google Scholar
  96. 96.
    E.Buchner, “Zymase aus getödteter Hefe,” Ber. deut. chem. Ges., 33 (1900), 3307–3310; E. Buchner and R. Rapp, “Alkoholische Gährung ohne Hefezellen,” ibid., 34 (1901), 1523–1530.Google Scholar
  97. 97.
    E. Buchner, H. Buchner, and M. Hahn, Die Zymasegärung (Munich, 1903), pp. 24–48.Google Scholar
  98. 98.
    E. Buchner, “Cell Free Fermentation,” Nobel Lectures, Chemistry 1901–1921 (Amsterdam, 1966), pp. 99–122.Google Scholar
  99. 99.
    H.Fischer, “Ueber Gärung,” Centralb. Bakt. (pt. II), 9 (1902), 353–356, 385–395.Google Scholar
  100. 100.
    H. Fischer, “Ueber Enzymwirkung und Gärung,” Sitzungsber. Niederrhein. Ges. Naturf. Heilkunde 1903, [A], 13.Google Scholar
  101. 101.
    Ibid., p. 14.Google Scholar
  102. 102.
    Ibid., p. 18.Google Scholar
  103. 103.
    E. Buchner, Die Zymasegärung pp. 26–27.Google Scholar
  104. 104.
    E. Nordenskiold, A History of Biology (New York, 1928), pp. 606ff.Google Scholar
  105. 105.
    H.Fischer, “Enzyme und Protoplasma,” Centralb. Bakt. (pt. II), 10 (1903), 452–457.Google Scholar
  106. 106.
    E.Buchner and W.Antoni, “Weitere Versuche über die zellfreie Gärung,” Z. physiol. Chem., 44 (1905), 227–228.Google Scholar
  107. 107.
    H.Fischer, “Ueber den Zustand der lebenden Substanz,” Z. physiol. Chem., 46 (1906), 206–208; E. Buchner, “Entgegnung an die Herren Th. Bokorny und Hugo Fischer,” Biochem. Z., 4 (1907), 230–234; H. Fischer, “Ueber den Unterschied zwischen lebender und lebloser Substanz,” Centralb. Bakt. (pt. II), 19 (1907), 656–660; H. Fischer, “Ueber Grenzgebiete des Lebens,” Naturwiss. Wochens., 7 (1908), 28–29; H. Fischer, “Meine angebliche Gegnerschaft gegen die Zymase-entdeckung,” ibid. (pt. II), 21 (1908), 610–614.Google Scholar
  108. 108.
    B.Leisering, “Hugo Fischer,” Ber. deut. bot. Ges., 58 (1940), 55–69.Google Scholar
  109. 109.
    J. R.Green, “On Vegetable Ferments,” Ann. of Bot., 7 (1893), 133–137.Google Scholar
  110. 110.
    J. R.Green, “On Vegetable Ferments,” Ann. of Bot., 7 (1893), 135.Google Scholar
  111. 111.
    A. Fischer, The Structure and Functions of Bacteria, trans. A. C. Jones (Oxford, 1900), p. 179.Google Scholar
  112. 112.
    A. Macfadyen, The Cell as the Unit of Life and Other Lectures (London, 1908).Google Scholar
  113. 113.
    M. W. Beijerinck and J. J. van Hest, Folia Microbiologica 4 (1916), vol. 2, p. 1. See E. Buchner and S. Skraup, “Neuere Ansichten über die Zymase”, Sitzb. phys.-med. Ges. Würzburg, 10 May 1912.Google Scholar
  114. 114.
    R. E. Kohler, (above, n. 2).Google Scholar

Copyright information

© President and Fellows of Harvard College 1972

Authors and Affiliations

  • Robert E. Kohler
    • 1
  1. 1.Burndy LibraryNorwalkUSA

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