Licence: In copyright
Credit: Reports to the Evolution Committee of the Royal Society. 1-5. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
11/526 page 7
![as our own views and modes of expression do not agree wholly with those of other writers on the subject. It may be premised that the first publication of the re-discovery was made in 1900 by de Vries,* and almost simultaneously by Corrensf and Tschermak.f There can be no doubt that the appearance of this group of papers constitutes at length a definite advance both in the general study of the physiology of reproduction and in the particular problem of the nature of Species. In 1865 Gregor Mendel published his discovery. His experiments are described in considerable detail, and the resulting law is stated with emphasis and precision. He at once perceived and lucidly enun- ciated what he regarded as the essential truth underlying the observed facts. A reader of this paper can hardly fail to recognise its masterly quality. By some strange chance it was ignored, and excepting a casual reference in Focke's ' Pflanzen-Mischlinge' (p. 110) there appears to be no allusion in literature to this remarkable performance. It is a fortunate circumstance that we need feel no hesitation in now accepting Mendel's account; for even if the original paper were such as to admit of doubt, the re-discovery comes to us with a large body of fresh evidence, the simultaneous work of three independent observei-s, con- firming Mendel on the main points. Mendel states that, like other investigators, he had been struck by the regularity Avith which offspring of certain hybrids reproduce the pure ancestral forms. But owing, as he supposes, to the com- plex natui-e of the cases studied and to want of accurate statistics, the precise facts had never been ascertained. Accordingly he set himself to work out some case from which every confusing element should as far as possible be excluded. After several trials he chose the varieties of Pisum sativum as best suited to his purpose. Besides other advantages, this species is well known to have the exceptional merit of being habitually self-fertilised, in N. Europe at least. From the many varieties of peas he first chose pairs of varieties, for crossing, in such a way that the members of each pair differed from each other in respect of one definite character. Of such pairs of characters he chose seven, namely: 1. Shape of seed, whether rounded m- irregularly angular and deeply wrinkled. 2. Colour of cotyledons [» endosperm], whether some shade of yellow or green. 3. Colour of seecl-skin, whether a brownish shade or white (in correla- tion with white flowers). 4. Shape of ripe pod, whether simply niHated or deeply constricted between the seeds. 5. Colour of unripe pod, whether a shade of green or bright yellow. 6. Position of flowers, ' O ' J y^. —^.m rt-. Versuchswesen in Oesterr.,' lOOO, 3, p. 465.](https://iiif.wellcomecollection.org/image/b22652188_0011.jp2/full/800%2C/0/default.jpg)
