Experiments in plant hybridisation / Mendel's original paper in English translation, with commentary and assessment by Sir Ronald A. Fisher, together with a reprint of W. Bateson's biographical notice of Mendel ; edited by J.H. Bennett.

  • Mendel, Gregor, 1822-1884. Versuche über Pflanzenhybriden. English
Date:
[1965]
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Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Experiments in plant hybridisation / Mendel's original paper in English translation, with commentary and assessment by Sir Ronald A. Fisher, together with a reprint of W. Bateson's biographical notice of Mendel ; edited by J.H. Bennett. Source: Wellcome Collection.

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    46 EXPERIMENTS IN PLANT HYBRIDISATION the purpose of propagation one pollen cell and one egg cell unite in Phanerogams * into a single cell, which is capable by- assimilation and formation of new cells to become an indepen¬ dent organism. This development follows a constant law, which is founded on the material composition and arrangement of the elements which meet in the cell in a vivifying union. If the re¬ productive cells be of the same kind and agree with the founda¬ tion cell [fertilised ovum] of the mother plant, then the development of the new individual will follow the same law which rules the mother plant. If it chance that an egg cell unites with a dissimilar pollen cell, we must then assume that between those elements of both cells, which determine opposite characters some sort of compromise is effected. The resulting compound cell becomes the foundation of the hybrid organism the development of which necessarily follows a different scheme from that obtaining in each of the two original species. If the compromise be taken to be a complete one, in the sense, namely, that the hybrid embryo is formed from two similar cells, in which the differences are entirely and permanently accommodated together, the further result follows that the hybrids, like any other stable plant species, reproduce them¬ selves truly in their offspring. The reproductive cells which are formed in their seed vessels and anthers are of one kind, and agree with the fundamental compound cell [fertilised ovum]. With regard to those hybrids whose progeny is variable we may perhaps assume that between the differentiating elements of the egg and pollen cells there also occurs a com¬ promise, in so far that the formation of a cell as foundation of * In Pisum it is placed beyond doubt that for the formation of the new embryo a perfect union of the elements of both reproductive cells must take place. How could we otherwise explain that among the offspring of the hybrids both original types reappear in equal numbers and with all their peculiarities ? If the influence of the egg cell upon the pollen cell were only external, if it fulfilled the rôle of a nurse only, then the result of each artificial fertilisation could be no other than that the developed hybrid should exactly resemble the pollen parent, or at any rate do so very closely. This the experiments so far have in no wise confirmed. An evident proof of the complete union of the contents of both cells is afforded by the experience gained on all sides that it is immaterial, as regards the form of the hybrid, which of the original species is the seed parent or which the pollen parent.