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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![times been asserted against the Spermatozoa or spermatic cor- puscules, are again brought forward ; they are said to be fecula or drops of oil, in which view I do not concur ; I have, how- ever, already stated my opinion on this subject in last year’s report. Starch occurs only in imperfectly formed pollinic vesicles ; not rarely in Conifere and in some water plants. I have also been able to observe in Muscari moschatum that in such imperfectly developed pollinic vesicles the masses of fe- cula which occur in them are converted into a gummy sub- stance and decompose into small molecules which have a very lively motion, resembling in every respect the phenomenon de- scribed by me in the cells of Marchantia polymorpha*. In some cells of this plant there occur instead of the common green cellular sap globules some large balls of a yellowish brown substance, which have been already observed and fi- gured by Mirbel. I followed up the formation of these masses from the globules of starch, which deliquesce and are then converted into a gum. When these globules are perfectly developed and of a yellowish brown colour, they decompose on the smallest touch into innumerable minute brownish mo- lecules, which for days exhibit the most lively motions, having an appearance similar to the motions in solutions of indigo, eum-arabic, &c., only somewhat more active. The second section treats of the coats of the pollen. A sim- ple membrane and one of a more compound structure are to be distinguished on the pollinic vesicles. Some plants exhibit but one tunic, others on the contrary three and even four. Most frequently but two tunics occur, and they are termed the inner and the outer coat; but where a duplication of one or both these membranes exists these names do not suffice, and on that account he proposes for the entire series of mem- branes, when they are all four present, the terms Intine, Hx- intine, Intexine, and Exine, which however cannot be admitted, for the fact is quite different to what M. Fritzsche supposesf. The inner tunic is from its simplicity easily distinguished from the outer membrane, and chemical agents afford ample means for separating them. Concentrated sulphuric acid de- stroys the inner membrane, but the outer one with its ap- * Wiegmann’s Archiv, 1837, part ili. p. 428. [+ Similar views are however entertained by H. Giraud. See his paper in the Annals of Natural History, vol. il. p. 399.—W. F.]](https://iiif.wellcomecollection.org/image/b33490065_0003_0082.jp2/full/800%2C/0/default.jpg)
