Chapters in modern botany / by Patrick Geddes.

  • Geddes, Patrick, Sir, 1854-1932.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Chapters in modern botany / by Patrick Geddes. Source: Wellcome Collection.

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    ever, at present impracticable, i.e. remains a problem for the experimental physiologist. Yet even the natural selectionist most satisfied with accounting for the change on the principle of the mechanically improving fly-trap is notwithstanding the very man empirically to help, if not anticipate us, by finding us a seedling varying in the required direction among a patch of young Sarracenia ; for on this and its offspring the experimentalist might best begin. All such experimental researches are as yet only in their infancy, but it is becoming admitted on all hands that as the past of the science lies mainly in systematic collections, in anatomical and microscopic analyses, so its future has to be sought in the physiological laboratory, the greenhouse, and the garden. Insect-OatcMng.—But how, the active minded observer will ask, does our curious helmet-like Darlingtonia pitcher keep its victims,—for though it is natural for an insect to creep into what doubtless appears to it a very inviting new kind of flower, why should it not creep out again ? A first difficulty is afforded by the incurved margins ; but this would not be enough to detain it; and here comes in the use of the relatively widely distended helmet-space with its innumerable transparent glassy panes let into its whole upper surface. The insect has eyes on the top and sides of its head, and sees abundant light above to spread its wings and beat itself upon the resisting roof and walls of the pitcher as persistently and as vainly as he does within our own window-casement. No doubt when he becomes tired and falls down over the entrance he may at times escape, but is more likely only to rest over it till he can again begin his struggles on the wing, while the adjacent opening, that of the fatal oubliette, is not only of much larger diameter, but of gently-sloping sides instead of repellent recurved margins. The walls of the leaf-tube substantially