Volume 3

The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours.

  • Kerner von Marilaun, Anton, 1831-1898.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours. Source: Wellcome Collection.

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    walled tissues is prevented by this position, and during the night the vertical position of the young leaves has this advantage, that by it radiation, that is to say, excessive loss of heat, is hindered. The young not yet completely developed foliage is in both these respects very sensitive, much more so than adult foliage, and this depends upon the fact that the latter is comparatively poor in watery contents, and the composition of the protoplasm has become altered. It may happen that in the same plant, under the same conditions of habitat and like conditions of temperature of air and soil, while the young leaves perish after bright nights in consequence of too great loss of heat, the fully-developed leaves suffer no injury. This brings us to the question, Wherein the damage to plants caused by great loss of heat actually consists? FREEZING AND BURNING. Pancratius, Servatius, and Bonifacius, whose names stand in the calendar against the 12th, 13th, and 14th of May, have popularly been called “ Eismanner” in southern Germany and Austria. They have received this nickname on account of the fall of temperature which takes place every year about the middle of May, the cause of which is not yet fully explained. Later in the summer such falls in temperature, connected with cooling of the atmosphere on a large scale, occur on certain days with some regularity; but these have not received so much notice because they are not so dangerous to field products, fruit and wine, as the relapses about the middle of the month of May. Moreover, although really cold days occur in June or July, they are never followed by a frost, while the three “Eismanner” of May usually bring with them severe frosts at night, even in the mildest regions of Central Eui’ope, thus doing incalculable mischief to vegetation. What first of all strikes us in a frozen plant-organ is that it has completely lost its elasticity. On bending and pressing back with the finger the frozen, stiffened foliage-leaf, a permanent fold is immediately produced; the leaf is broken along this fold, and can no longer resume its former position. At the time of breaking a noise is heard like the crushing of pounded ice, and as a matter of fact it is actually crystallized ice formed in the interior of the leaf which is broken by the pressure and causes this crunching to be heard. As the tempera- ture rises during the day, the frozen plants become thawed, but most of them retain no longer the elasticity which they possessed before the frost. The leaves hang down flaccidly, are of a different green, and are more transparent than formerly. The surface is damp, and the epidermis is easily detached from the deeper tissue-layers. Gradually the languid leaves shrivel up, become dried, and assume a brown or black colour. They entirely resemble burnt or charred leaves, and the farmer says that the frost has burnt them. What takes place in the interior of the plant on account of this freezing? The idea which botanists once held is as follows: the watery cell-sap of the plants stiffens to ice; but the ice takes up a larger space than was occupied by