By Staffan Müller-Wille (University of Exeter) and Kersten Hall (University of Leeds)


On this website, we present a new English translation of Gregor Mendel's seminal publication, “Versuche über Pflanzen-Hybriden” (Experiments on Plant Hybrids), which appeared a little more than 150 years ago, in 1866, and is regarded as one of the founding documents of genetics. We present our translation along with a facsimile of the original publication, a transcription of the German text, and detailed glosses on almost each and every sentence.

This is clearly not the first English translation, as we will set out in more detail below, and another one by Scott Abbott and Daniel J. Fairbanks has just appeared in the journal Genetics. We do not think that any of the existing translations are particularly bad, nor do we consider ours as the definitive one that should replace earlier ones. What we want to offer instead is a window onto the original German text for those who know little or no German at all. Our translation thus serves as a resource to make up ones own mind about how best to translate Mendel.

Below we set out our rationale in more detail. You may want to skip this, and just enter the translation directly by clicking the button below. The layout, we hope, is intuitive and original. You have the option to go through the translation page by page, with transcription and translation side by side and a thumbnail of the original that opens to display a facsimile when holding the mouse pointer over it. Sentences that break over a page are displayed in full, with the part of the sentence that straddles the next or previous page highlighted in a different font colour. If a particular sentence catches your attention, and you want to know more about it, you can just click it, and you will be taken to a sentence by sentence view, again displaying transcription and translation of the sentence side by side, and with detailed glosses on certain words or phrases in a separate comments section. As viewing transcription and translation side-by-side is the aim, the layout has not been optimized for mobile viewing; best results are obtained on laptops, desktops and tablets. Please send any errors (technical or typo) to This email address is being protected from spambots. You need JavaScript enabled to view it..

Mendel and the History of Genetics

Ask a biologist to name the three publications which have defined the intellectual landscape of their subject and the chances are that, alongside Darwin’s On the Origin of Species (1859) and James Watson and Francis Crick’s publication of the structure of DNA in Nature in April 1953, will be a paper published in 1866 by the Augustinian monk Gregor Johann Mendel (1822–1884) about “Experiments on Plant Hybrids” (Mendel 1866). The British evolutionary biologist Sir Gavin de Beer went so far as to say, “It is not often possible to pinpoint the origin of a whole new branch of science accurately in time and space ... But genetics is an exception, for it owes its origin to one man, Gregor Johann Mendel” (De Beer 1966, p. 154). Certainly a cursory glance through most A-level and undergraduate biology textbooks will find photographs of Mendel accompanied by figure legends revering him as the founding father of genetics (Kampourakis 2013). Further drama is often added by portrayals of Mendel as being a lone, neglected genius whose work was way ahead of its time and who, pottering around in a garden in a remote corner of the Austro-Hungarian empire, was consigned to scientific oblivion until the rediscovery of his work around 1900.

What then did Mendel do to justify the accolades heaped upon him by biology textbooks? Working in his garden at the monastery in Brno, in what is now the Czech Republic, Mendel crossed varieties of the species Pisum sativum (the common garden pea) exhibiting differences with regard to particular traits. By meticulously recording the numerical ratios in which these traits appeared in each generation of progeny, Mendel derived conclusions that later became known as Mendel’s two laws. The first of these laws (the Law of Segregation) states that when a sex cell, or gamete, is formed, only the disposition for one form of the trait can enter the newly formed gamete. The second law, or Mendel’s Law of Independent Assortment, maintains that this process occurs independently of other traits. So, for example, whether a newly formed sex cell receives a disposition for a particular flower colour occurs completely independently of the disposition it receives for seed shape.

The significance of Mendel’s work is that the precise numerical ratios he observed have subsequently been interpreted as providing the basis for our contemporary understanding of genes as small pieces of DNA determining inheritance. But how much of what we today call “Mendelian genetics” can actually be found in Mendel’s original paper? This was a question raised in a paper entitled “Mendel — no Mendelian?” published in 1979 by the historian of science Robert Olby. In his paper, Olby argued that far from anticipating general laws of heredity, Mendel was actually working in a long established tradition of naturalists interested in the formation of new species through hybridisation of pre-existing species. Olby went even further and claimed that Mendel never actually believed that the traits he observed were controlled by pairs of discrete particulate entities within the cell — what in our contemporary parlance we would call genes or alleles (Olby 1979).

Olby’s argument did not go unchallenged (Orel and Hartl 1994), but it provides a good example to show how, far from being set in stone, Mendel’s work is subject to interpretation, and has been so, in fact, since his paper’s so-called re-discovery in 1900. The paper itself was immediately reprinted by one of its re-discoverers, the Austrian agriculturalist Erich von Tschermak-Seysenegg, in a prestigious series of classics in the history of the “exact” sciences, which had been founded in 1889 by the famous Baltic-German chemist Wilhelm Ostwald (1853–1932). Unlike today, most academics back then were able to read German (and usually a couple of other languages). And so, within a year of having caught the attention of a few highly specialized botanists, Mendel’s paper was widely available to an international, educated audience and found itself in the company of publications by the likes of Galileo Galilei, Isaac Newton and John Dalton (Mendel 1901a).

Other Translations

The first English translation followed soon after Tschermak produced his edition. It was commissioned by the English naturalist William Bateson (1861–1926) for the Royal Horticultural Society, and appeared in the Society’s Journal in 1901, next to an advertisement for “Carters Grass Seeds as used at Lords and The Oval and other Leading County Cricket Grounds” (Mendel 1901b). The translation had been prepared by the one-time poet and expert on British ferns Charles T. Druery (1843–1917), and we are referring to it as Druery's translation in our comments. It was provided with an introductory note by Bateson in which he perceptively remarked that “the whole paper abounds with matters for comment and criticism”, but also that it can be “doubted whether in his own day, [Mendel’s] conclusions could have been extended”. In 1902, Bateson included Druery’s translation “with corrections and modifications” in his polemic Mendel’s Principles of Heredity: A Defence (Mendel 1902). This version we will refer to as Bateson's translation in our comments.

Bateson’s translation has been the basis of countless reprints. The US-American geneticist William E. Castle included it in his Genetics and Eugenics, which became a very popular textbook (Mendel 1916). The publisher, Harvard University Press, subsequently decided to re-issue the translation as an inconspicuous brochure, obviously for study and working purposes. This version came out in fourteen editions between 1916 to 1965, the last edition still being in print (Mendel 1965a). Also in 1965, the year which marked the 100th anniversary of Mendel’s paper, Bateson’s translation was reprinted with a detailed “commentary and assessment” by the statistician and population geneticist R. A. Fisher (Mendel 1965b), who had sparked a major controversy in 1936 by demonstrating that some of Mendel’s results were “too good to be true” (Fisher 1936). The MendelWeb provides ready online access to this translation today, with useful notes and a glossary produced by Roger B. Blumberg. As Blumberg explains: “Although this translation may strike readers of German as painfully inaccurate in places, its significance in the history of genetics is beyond dispute; when English and American biologists and students of biology read Mendel in the first decades of the 20th century, they most often read the Druery-Bateson translation”.

The inaccuracies mentioned by Blumberg had not gone unnoticed. A new translation was made by the Drosophila-geneticist Eva R. Sherwood (Mendel 1966), which was included in a collection of Mendeliana entitled The Origin of Genetics: A Mendel Source Book that she and Curt Stern (1902–1981) edited in 1966 — that is, one-hundred years after the correct year of publication of Mendel’s paper, but of course coming a year late to really beat the Fisher edition. As Curt Stern recalled in his foreword to the collection, his colleagues Leslie Clarence Dunn (1893–1974), retired from Columbia University, and Alan Robertson from the Institute of Animal Genetics in Edinburgh, had drawn his attention to errors in Bateson’s translation. Subsequent “careful comparison with the original German text showed not only a number of mistakes which fundamentally changed the meaning of Mendel’s sentences but in addition so many other inaccuracies that Eva Sherwood undertook a completely new translation” (Stern 1966, p. vii). Not much is known about the author of this transaltion, apparently a gifted student of Stern's who died shortly after the translation came out. More faithful to the original style and wording of Mendel, Sherwood’s translation has served as the basis for the interesting “guided study” of Mendel’s paper that was published by Alain F. Corcos and Floyd V. Monaghan in 1993. Overall, however, it has never matched Bateson’s translation in popularity. We refer to this translation as Sherwood's in our comments.

Finally, just as we were finishing the proofs of our translation, a third translation came out as an open-access article in the journal Genetics (Mendel 2016). Its authors — Scott Abbott, Professor of Integrated Studies, Philosophy and Humanities at Utah Valley University, and Daniel J. Fairbanks, Professor of Biology at the same institution and a renowned Mendel scholar, — stress in an accompanying article that their translation was motivated by two objectives (Fairbanks and Abbott 2016). First, “to be more accurate than the Druery-Bateson translation and more accessible than the Sherwood–Stern translation”. And second, “given that a German translation of Origin of Species was probably the only source originally written in English that influenced Mendel” to make “an exhaustive effort to employ Darwin’s phraseology ... when choosing English words in the translation”. They achieved the second objective of “Darwinizing” Mendel, as they put it, by “cross-comparing German words and phrases in Mendel’s paper” with those in H. G. Bronn's German translation of Darwin's Origin (1863), a copy of which Mendel possessed and annotated, and then “identifying the corresponding words or phrases in Darwin’s original English”. This provides their translation “with a decidedly 19th century Darwinian tone, which, of course, is consistent with the time when Mendel presented and published his paper” (Fairbanks and Abbott 2016, p. 403).

Why This Translation

So, do we really need yet another translation of Mendel's paper? We thought so, and we still think so despite being “scooped”. Our translation combines the approaches of Sherwood and Abbott and Fairbanks. On the one hand, it is quite literal, adhering closely to the syntax and terminology of the German original in order to make it easier for users to compare the translated text with the original. What we thereby gained in transparency, we certainly often lost in elegance of the resulting translation. On the other hand — using similar strategies as Abbott and Fairbanks, but based on a broader range of sources, — we have also been careful to preserve the distinctly nineteenth-century tone of Mendel's paper and avoid any anachronisms in our translation. We would also like to emphasize that we have not tried to reinvent the wheel. Our first “raw” translation was done without recourse to earlier translations, but we have happily followed Bateson or Sherwood in cases where we thought their translation was particularly ingenious.

While we, like most translators, believe that there are ways to be more or less accurate in translation, we are also aware that semantic relations between different languages are not one-to-one but many-to-many. Other translations therefore retain their value, which is why we have included alternative readings from earlier translations in our comments. While Bateson's translation was indeed inaccurate in places (beginning with the title, as we shall see below), it also was in many ways far more sensitive to the context of nineteenth-century biology than Sherwood's. And while Sherwood was guilty of a few anachronisms, she often found ingenious solutions to problems posed by Mendel's syntax. It was too late to consider Abbott and Fairbank's new translation in our comments, but we hope to learn from, and appreciate their effort, in a future iteration of our project. What neither of the previous translators did at any length, however, is discuss alternative readings or provide explicit reasons for their choices. This is where our translation differs. It is accompanied by detailed notes, furnishing a critical apparatus with details on the German original, including Mendel's manuscript and possible sources he drew upon, how earlier translators rendered certain words and phrases, and the reasons that made us choose a different translation. For this, we have used a taylor-made web-design with editing functionalities that will allow us to update our translation and commentary in the future.

Such an exercise can reveal many subtle points that tell us a lot about Mendel’s reasoning and its reception by later geneticists. Already the title of Mendel’s paper offers a good example. Druery and Bateson rendered the German original — “Versuche über Pflanzen-Hybriden” — as “Experiments in plant hybridisation”, insinuating that Mendel’s experiments should be understood as an exercise illuminating a much more general phenomenon. Sherwood gave us a much more literal translation with “Experiments on Plant-Hybrids”. Even this translation, however, does not capture the sense of the German unambiguously. The German über can be translated by "on”, but not in the sense that plant-hybrids were the objects of Mendel’s experiments, but rather in the sense that they were the very subject of his experiments, the topic he wanted to scrutinize by way of experiment. The most literal, but rather awkward translation would therefore render the title as “Experiments about Plant-Hybrids.” Since “Experiments on Plant-Hybrids” has become widely accepted as the correct translation in the English-speaking world — Abbott and Fairbanks use it as well — we decided to retain it. The difference may seem subtle, but preposition choice here can give an important steer to how one understands Mendel’s aims, particularly given Olby’s view that Mendel’s real interest was in hybridization as a process giving rise to new species.

Mendel’s precise understanding of the term ‘species’ is itself another important concern. Here, Druery and Bateson were more consequential in almost always choosing “species” when Mendel used the German Art. By contrast, Sherwood renders Art as ‘variety’ or ‘form’ or ‘stock’ most of the time. The explanation of her more varied vocabulary lies in the changing understanding of species. Bateson was still familiar with a nineteenth-century meaning of the term that Mendel had in mind, according to which plant forms differing by a few heritable traits, or even only one, belonged to different species; in the case of Pisum such varieties were even referred to by different Linnaean binomials by contemporary botanists. This understanding of species vanished in the aftermath of the evolutionary synthesis in the late 1930s. For the translator, the issue gets even more complicated by the fact that Mendel occasionally used the Latin expression Species (capitalized according to German orthographic rules) in order to single out taxonomic units that were distinguished by many traits; and he used this word interchangeably with gute Art or “good species” — an expression that Darwin also used in the Origin.

Many commentators have remarked on the fact that Mendel never used the German counterpart for heredity or inheritance, Vererbung. Only twice in his published and unpublished writings did he use the verb vererben, and in these instances in order to emphasize that a certain trait was not inherited. This does not mean, as our translation effort has revealed, that transmission talk was completely absent. Occasionally, Mendel uses a typically German verb construction — übergehen ... auf — that previous translators have rendered as “are transmitted to”. Übergehen is a peculiar expression, however. Since it is an intransitive verb, it does not suffer the passive voice, nor can it have a direct object. There is no straightforward equivalent for this in English. In German, übergehen is often used in the context of inheritance of landed property or titles, and hence for the inheritance of indivisible and inalienable goods. This may serve to provide further evidence that Mendel’s understanding of hereditary mechanisms was not the same as that of later geneticists.

A final example may suffice to show what details a reflective translation exercise can reveal. Of particular interest to anyone trying to locate the current concept of genetics in Mendel’s paper of 1866 are the different ways in which he talked about the relationship between the traits (Merkmale) that he observed and the dispositions for these traits within the germ cells. While the first half of Mendel’s paper exclusively concerned itself with external traits, the second half, from section 9 onwards, also contains speculations as to the state of affairs within reproductive cells. The two main terms that he used in these discussions referred to fertilised cells possessing some kind of generative capacity (Anlage), or being composed of elements (Elemente), responsible for the production of the trait. At one point Mendel surmises that in hybrids, these elements fail to reach a “compromise between the conflicting elements” (Ausgleichung ... der widerstrebenden Elemente). Widerstrebend conjures images of struggle and active resistance, while Ausgleichung connotes a settlement of conflict by negotiation — in short, Mendel ascribes agency to the elements that unite in a newly fertilized cell. Sherwood has “balance between the antagonistic elements” where Druery and Bateson speak of an “arrangement between the conflicting elements”. To contemporary readers, both translations hide much of Mendel’s vitalist language which is more reminiscent of the language of German Naturphilosphie than of twentieth-century genetics. They also hide the distinct political undertones these terms must have had for Mendel's contemporaries who witnessed the negotiations that came to be known as the “Austro-Hungarian Compromise” in 1867.

Translation Basis

Mendel's paper first appeared in volume IV of the journal Verhandlungen des naturforschenden Vereins zu Brünn, which covered papers that had been read at the monthly gatherings of the Brno naturalists' association in 1865, but was published in 1866. Mendel presented his paper, in two parts, at meetings on February 8 and March 8, 1865, respectively (a full pdf of the journal volume is available from Biodiversity Heritage Library). Reports in the daily press on Mendel's two presentations reveal that in the first session Mendel covered the first eight sections of his paper, while in the second session sections 9, 10 and 11 were read in which Mendel proposed theoretical interpretations of his results (Olby and Gautrey 1968, pp. 7–9). A manuscript in Mendel's hand has been preserved, which is very close to the printed version, some orthographic differences and printer's errors notwithstanding. It is likely, though not proven, that this is the manuscript that Mendel actually read at the Brno naturalist association's meeting. A facsimile of the original manuscript was reproduced in the journal Der Züchter (now Theoretical and Applied Genetics) in 1941 (Mendel 1941), and a full transcription was published as a “revised edition of Mendel's classic paper” in Kříženecký (1965a, pp. 57–92).

As a basis for our translation, we have neither used the original manuscript, nor the version that was published in the journal, but an offprint. A note on the original manuscript reveals that Mendel ordered 40 offprints, of which six have been tracked down. For our translation, we used a pdf-file of an offprint that is available online from the Virtual Laboratory and has some corrections in Mendel's hand. These corrections are included in our transcription within square brackets. We decided to use an off-print for our translation because it was offprints that at least two of Mendel's rediscoverers, Hugo de Vries and Carl Correns, relied on, and because the corrections Mendel entered manually in some of the offprints demonstrate that this can be considered his final, “authorized” version. On the original manuscript and publication history, see Kříženecký (1965b), Weiling (1970) and Orel (1996, pp. 273–276). Czihak (1984) contains a facsimile of another offprint which has the same corrections by Mendel as the one we used for our translation.


We would like to thank the British Society for History of Science for initial financial support for the raw translation, and for covering the costs of web-design. Particular thanks go to Greg Radick for his unfailing belief that, one day, the translation would see the light of the day. Staffan Müller-Wille is grateful to Vítězslav Orel (1926-2015), who first inspired him many years ago to undertake this project, Robert Meunier, who was of invaluable assistance in a very early stage of the project, and Pavel Paleček and Ondřej Dostál for their hospitality during a visit to Brno that allowed him to study Mendel's annotations in Darwin's Origin and Gärtner's Versuche und Beobachtungen. A big thank you, last but not least, to Michel Durinx, not only for developing an ingenious interface for working on the translation and commentary, but also for his continuous attention to the countless typos, inconsistencies, and simply mistakes we produced as time went by.

How to Cite This Translation

Gregor Mendel (2016). Experiments on Plant Hybrids (1866). Translation and commentary by Staffan Müller-Wille and Kersten Hall. British Society for the History of Science Translation Series. URL=

Unambiguous reference to a page or sentence of the commented translation can be made by using the full URL. For example, is the stable address for the translation of and commentary on the eighth sentence on the third page of Mendel's original publication, where the “/2016” in the URL refers to the original edition (by year). As any revised editions will similarly include their year of publication in the URL of each page and sentence, previous editions will remain available by this mechanism; importantly, citations will remain consistent even if the commentary or translation they refer to gets updated in a later edition.


  • Corcos, Alain F. and Floyd V. Monaghan (1993). Gregor Mendel’s Experiments on Plant Hybrids: A Guided Study. New Brunswick, N.J.: Rutgers University Press.
  • Czihak, Gerhard (1984). Johann Gregor Mendel (1822–1884). Dokumentierte Biographie und Katalog zur Gedächtnisausstellung anläßlich des hundertsten Todestages mit Facsimile seines Hauptwerkes: “Versuche über PfIanzenhybriden”. Salzburg: Im eigenen Verlag.
  • De Beer, Gavin (1966). “Genetics: The Centre of Science”. Proceedings of the Royal Society of London. Series B, Biological Sciences 164, no. 995: 154–66.
  • Fairbanks, Daniel J., and Scott Abbot (2016). “Darwin’s Influence on Mendel: Evidence from a New Translation of Mendel’s Paper.” Genetics 204, no. 2: 401–405.
  • Fisher, Ronald A. “Has Mendel’s Work Been Rediscovered?” Annals of Science 1, no. 2 (1936): 115–137.
  • Kampourakis, Kostas (2010). “Mendel and the Path to Genetics: Portraying Science as a Social Process.” Science & Education 22, no. 2: 293–324.
  • Kříženecký, Jaroslav (1965a). Fundamenta Genetica. Prague: Publishing House of the Czechoslovak Academy.
  • Kříženecký, Jaroslav. (1965b). Gregor Johann Mendel. 1822–1884. Texte und Quellen zu seinem Wirken und Leben. Leipzig: Johann Ambrosius Barth.
  • Mendel, Gregor (1866). “Versuche Über Pflanzen-Hybriden”. Verhandlungen des naturforschenden Vereines zu Brünn 4 (1865): 3–47.
  • Mendel, Gregor (1901a). Versuche Über Pflanzenhybriden: Zwei Abhandlungen, 1865 Und 1869, edited by Erich Tschermak. Vol. 121 of Ostwald’s Klassiker der exakten Wissenschaften. Leipzig: Wilhelm Engelmann.
  • Mendel, Gregor (1901b). “Experiments in Plant Hybridisation”, [translated by Charles T. Druery], with an introductory note by W. Bateson. Journal of the Royal Horticultural Society 26, part 1: 1–32.
  • Mendel, Gregor (1902). “Experiments in Plant-Hybridisation”. In William Bateson, Mendel's Principles of Heredity: A Defence. Cambridge: At the University Press: 40–95.
  • Mendel, Gregor (1916). “Experiments in Plant-Hybridisation”. In William E. Castle, Genetics and Eugenics: a textbook for students of biology and a reference book for animal and plant breeders. Cambridge, Mass.: Harvard University Press: 281–321.
  • Mendel, Gregor (1941). “(Originalhandschrift): Versuche über Pflanzen-Hybriden”. Der Züchter 13: 221–268.
  • Mendel, Gregor (1965a). Experiments in Plant Hybridisation. Cambridge, Mass.: Harvard University Press.
  • Mendel, Gregor (1965b). “Experiments in Plant Hybridisation”. In Gregor Mendel, Experiments in Plant Hybridisation, with commentary and assessment by Ronald A. Fisher, edited by J. H. Bennett. Edinburgh and London: Oliver & Boyd: 7–51.
  • Mendel, Gregor (1966). “Experiments on Plant Hybrids”, translated by Eva R. Sherwood. In The Origin of Genetics: A Mendel Source Book, edited by Curt Stern and Eva R. Sherwood. San Francisco: W. H. Freeman: 1–48.
  • Mendel, Gregor (2016). “Experiments on Plant Hybrids”, translated by Scott Abbott and Daniel J. Fairbanks. Genetics 204, no. 2: 407–422.
  • Olby, Robert C. “Mendel — No Mendelian?” History of Science 17, no. 1 (1979): 53–72.
  • Orel, Vítezslav (1996). Gregor Mendel: The First Geneticist. Oxford: Oxford University Press.
  • Orel, Vítezslav, and Daniel L. Hartl. “Controversies in the Interpretation of Mendels Discovery”. History and Philosophy of Life Sciences 16, no. 3 (1994): 436–55.
  • Stern, Curt (1966). “Foreword”. In The Origin of Genetics: A Mendel Source Book, edited by Curt Stern and Eva R. Sherwood. San Francisco: W. H. Freeman: v–xii.
  • Weiling, Franz (1970). “Geschichte des Textes der ‘Versuche’ sowie textkritische Bemerkungen”. In Gregor Mendel, Versuche über Pflanyen-Hyrbiden, Vol. 6 of Ostwalds Klassiker der exakten Wissenschaften, Neue Folge. Braunschweig: Vieweg: 15–20.