Chapters in modern botany / by Patrick Geddes.

  • Geddes, Patrick, Sir, 1854-1932.
Date:
1899
Catalogue details

Licence: Public Domain Mark

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

    53/230 (page 31)
    paring the form in question with that of nearly related plants ; partly by observation of the young plants and their gradual development; partly by attention to those mon- strosities which often reveal the secret of strange structures. It is only when the student has learned to place himself at the standpoint of several distinct theories, and to state and weigh these impartially, that he becomes able to give his adherence to one or other view. Nor can he fully do this without reading for himself the original papers, and perhaps reinvestigating the subject for himself after all. Bladderwort.—Our tour round the world in search of pitcher-plants may find appropriate completion in the dis- covery of one not less interesting almost at our own doors. In marshy lochs and mountain tarns the Common Bladder- wort makes itself conspicuous for a month or two in summer, when from the floating stem the flower-stalk rises bearing quaint bright golden blossoms, somewhat orchid- like in appearance, which, though considered by some to represent a complex developed fomi of the primroses, are probably more closely allied to the foxglove, snap- dragon, and toad-flax. At other times the plant is not so readily seen, for it floats in the water, and its leaves are small. Like some other aquatic plants the water bladderworts have no roots, and the sti^aggling stem bears numerous, much-divided slender leaves. Among these are hundreds of little bladders. From the main submei'ged stem of Utricularia vulgaris, and yet more markedly in tropical species, peculiar thin shoots, which Gcebel calls aerial shoots, rise to the surface, and bear leaves slightly different from those on the other parts of the stem. It seems likely that this part of the plant is of special use in effecting interchange of gases with the air. Each bladder—shown by its mode of development to be