Volume 3
A report on the progress of vegetable physiology during the year 1837 ... / Translated from the German by William Francis.
- Franz Meyen
- Date:
- 1839
Licence: Public Domain Mark
Credit: A report on the progress of vegetable physiology during the year 1837 ... / Translated from the German by William Francis. Source: Wellcome Collection.
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![Schleiden on the act of impregnation are correct, and whether we must dismiss in consequence our old views respecting the sexes of plants. I am of opinion (and shall endeavour to prove it in the third volume of my ‘ Physiology’) that M. Schleiden’s observations have considerably advanced our knowledge re- specting the plastic process in the impregnation of plants; but it will be shown that the old notions of the sexes of plants must be retained as before, even setting entirely aside the formation of bastards, which could not be explained according to the doc- trine that the anther must be considered as a female ovarium. We return at present to the consideration of the embryo. Upon its first appearance, says M. Schleiden, the embryo is to be recognized as a membranous cylinder, rounded and closed superiorly, open inferiorly, and filled with organisable matter, which is gradually converted into cells, beginning from above downwards, during which process the cellular nuclei become apparent, which appear at all times to perform a principal part in the formation of cells*. This cylinder M. Schleiden regards as an axile formation, the upper end of which expands into a globe, whence the cotyledons are developed, the apex (that is to say the axis) remaining more or less evidently free, by which it is proved that the axis exists before the leaves. The first appearance of the embryo and the formation of its parts is naturally of the highest importance for the mor- phological explanation of the various parts of the grown plant : * With respect to the function of the cellular nucleus several important discoveries have been made in the current year (1838), which in many cases perfectly explain the formation of the cellular tissue of plants. [have also observed in many cases that the cellular nucleus makes its appearance originally as a simple globular mucous cell provided with a solid spherical nucleus, and only at a subsequent period is converted into the disc-like forma- tion which is very frequently attached by excessively delicate, and at times also ramified threads to the inner surface of the cell. From the substance of this disc, the first rudiments (the nuclei) of the amylum globules and of the other cellular sap globules, which for some time adhere to the disc and form a circle around the more solid nucleus, are formed. Subsequently the mucous substance of the disc disappears, the starch globules, &c. increase in size and still remain for some time in that circular position, in which the green cellular sap globules are frequently found in the cells of the epi- dermis. In very young potatoes and in some species of Cactus I have been able to follow up this formation.—Rep. [Dr. Meyen here evidently alludes to M. Schleiden’s admirable memoir on Phytogenesis, which at present oc- cupies so much of the attention of continental botanists, and of which an English translation appeared in the 6th Part of Taylor’s Scientific Memoirs. We] ——](https://iiif.wellcomecollection.org/image/b33490065_0003_0135.jp2/full/800%2C/0/default.jpg)
