. The elements of structural botany with special reference to the study of Canadian plants ... Plant physiology; Plant anatomy. KXAMINATION OP A MOSS. 191 3il. The slender scape-like stalk which rises above the leaves is technically called the seta, or bristle ; in the ^eft-hand part of the figure (c) the upper end of the seta is covered by a hairy cap, the cahjptra. In the right-hand por- tion the calyptra has been re- moved, disclosing a little pod, variously spoken of as the theca, or urn, or capsule, or sporangium. Fig. 241 is an enlarged view. This capsule is closed at the top by a circul
. The elements of structural botany with special reference to the study of Canadian plants ... Plant physiology; Plant anatomy. KXAMINATION OP A MOSS. 191 3il. The slender scape-like stalk which rises above the leaves is technically called the seta, or bristle ; in the ^eft-hand part of the figure (c) the upper end of the seta is covered by a hairy cap, the cahjptra. In the right-hand por- tion the calyptra has been re- moved, disclosing a little pod, variously spoken of as the theca, or urn, or capsule, or sporangium. Fig. 241 is an enlarged view. This capsule is closed at the top by a circular lid, the opei-culum, which falls away when the cap- sule is mature, thus allowing the escape of the spores, which are produced in it. The spores are developed upon the surface of a central column which rises from the bottom of the capsule, and which is known as the columella. The opening through which the spores escape is called the stoma, and a good lens reveals the fact that around the stoma there is a circle (sometimes two) of minute teeth, known collectively as the peristome. In the Moss now be- fore us the peristome consists of sixty-four teeth. In other Mosses the number varies, being always, however, some power of 2 ; either 4, or 8, or 16, or 32, or 64. Occasionally the teeth are altogether absent, Figr. 239.—Two fertile stems of a Moaa (Polytrichum commmi^ of the Qiitural size; at c the calyptra i? eeen enveloping^ the capsule. (Wood and Steplel,. Fig. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Spotton, Henry Byron, 1844-. Toronto, W. J. Gage & Co
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Keywords: ., bookcentury1800, bookdecade1890, booksub, booksubjectplantanatomy
