Elementary botany (1898) Elementary botany . elementarybotany00atki Year: 1898 FERNS. 169 351. Opening of the sporangium and dispersion of the spores.—If we take some fresh fruiting leaves of the Cpristmas fern, or of any one of many of the species of the true ferns just at the ripening of the spores, and place a portion of it on apiece of white paper in a dry room, in a very short time we will sde that the paper is being dusted with minute brown objects which fly out from the leaf. Now if we take a portion of the same leaf and place it under the low power of the microscope, so that the full
Elementary botany (1898) Elementary botany . elementarybotany00atki Year: 1898 FERNS. 169 351. Opening of the sporangium and dispersion of the spores.—If we take some fresh fruiting leaves of the Cpristmas fern, or of any one of many of the species of the true ferns just at the ripening of the spores, and place a portion of it on apiece of white paper in a dry room, in a very short time we will sde that the paper is being dusted with minute brown objects which fly out from the leaf. Now if we take a portion of the same leaf and place it under the low power of the microscope, so that the full rounded sporangia can be seen, in a short time we will note that the sporangium opens, the upper half curls backward as Fig. 207. Four pinnae of adiantum, showing recurved margins which cover the sporangia. shown in fig. 211, and soon it snaps quickly, to near its former position, and the spores are at the same time thrown for a consid- erable distance. This movement can sometimes be seen with the aid of a good hand lens. 352. How does this opening and snapping of the sporan- gium take place ?—We are now more curious than ever to see just how this opening and snapping of the sporangium takes place. We should now mount some of the fresh sporangia in water and cover with a cover glass for microscopic examination. A drop of glycerine should be placed at one side of the cover glass on the slip so that the t:d'^c of the glycerine will come in touch with the water. Now as one looks through the microscope to watch the
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