. Elementary biology; an introduction to the science of life . I I Fig. 127. Spores of fern (7, back of a fern leaflet, showing arrangement of sori (singular, sorns), or clusters of spore cases ; b, section through a sorus, showing spore cases with inclosing layer of thin tissue ; c, single spore case, greatly enlarged ; d, same bursting open and dis- charging spores by the sudden straightening out of a row of thick-walled cells ; e, spores, greatly enlarged ; /, spore germinating into a new plant the leafy stem. Ferns produce spores in little capsules found in groups on the undersurface of th
. Elementary biology; an introduction to the science of life . I I Fig. 127. Spores of fern (7, back of a fern leaflet, showing arrangement of sori (singular, sorns), or clusters of spore cases ; b, section through a sorus, showing spore cases with inclosing layer of thin tissue ; c, single spore case, greatly enlarged ; d, same bursting open and dis- charging spores by the sudden straightening out of a row of thick-walled cells ; e, spores, greatly enlarged ; /, spore germinating into a new plant the leafy stem. Ferns produce spores in little capsules found in groups on the undersurface of the leaves, or, in some species, right under the edge (Figs. 126 and 127). 341. Spores in animals. A number of one-celled animals related to the ameba produce spores in a manner that can be compared to the process described in the yeast plant. But the number of spores produced is usually very large, and in some cases the spores do not have thick walls, but are rather active. The protozoon that is the cause of malaria is related to the ameba, and is parasitic on the red blood corpuscles. When the mass of protoplasm has grown to its limit, it breaks up into a large number of pieces, and these are thrown into the
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishe, booksubjectbiology
