Growth and tropic movements of plants / by Sir Jagadis Chunder Bose.

  • Jagadish Chandra Bose
Date:
1929
Catalogue details

Licence: In copyright

Credit: Growth and tropic movements of plants / by Sir Jagadis Chunder Bose. Source: Wellcome Collection.

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    may even be missing. The difficulty is obviated by accurate adjustment of the plate in a vertical plane by means of regulating screws. Experimental Accessories The soil in a flower-pot is liable to be disturbed by irrigation and the record be consequently vitiated. This is obviated by wrapping the root, imbedded in a small quantity of soil, in a piece of cloth, the lower end of the plant being held securely by the clamp of the plant-holder. In order to subject the plant to the action of gases and vapours, or to variation of temperature, it is enclosed in a cylindrical chamber constructed of a sheet of mica, with an inlet and an outlet pipe. The chamber is maintained in a humid condition by means of a sponge soaked in water. Vapours and gases can be easily introduced or removed from the plant-chamber ; variation of temperature is simply effected by blowing in heated or cooled water-vapour. Any quickly growing organ of a plant will be found suitable for the following experiments ; complications arising from circumnutation may be avoided by employing either radial organs, such as flower peduncles, buds, or the pistils of certain flowers, or the limp leaves of various species of grass. It is advisable to select specimens in which the growth is fairly uniform. I append a repre- sentative list of different specimens in which, under favour- able conditions of season and temperature, the rates of growth may be as high as those given below : Table 1.—Average Rate of Growth in Different Specimens. Peduncle of Zephyranihes . o • 7 mm. per hour Leaf of grass i • io ,, Pistil of Hibiscus flower 1-20 „ .Seedling of Wheat i • 6o ,, ,, ,, Flower-bud of Crinum 2 * 20 • — v-' y ) y y y y Seedling of Scirpus Kysoor • 3 * > > > y > > The specimen employed for experiment may be an entire plant ; it is, however, more convenient to employ