. Essentials of botany. Botany; Botany. THE PTERIDOPHYTES 283 363. Asexual Reproduction, Spore-Cases and Spores.^ — Pick out some spore-cases from a sorus (Fig. 204, C, D), mount them in water, examine with , and note : (a) The stalk. (6) The spore-cases proper. Draw. (c) The partial ring of thick-walled cells enclosing the spore-case. (d) The spores. These should also be examined with Draw. The spores are scat- tered by the splitting open of the spore-case very dry, pulled apart by the elastic ring (Fig. 204, D). 364. The Gameto- phyte (Prothallium) and Sexual Reproduction. — M
. Essentials of botany. Botany; Botany. THE PTERIDOPHYTES 283 363. Asexual Reproduction, Spore-Cases and Spores.^ — Pick out some spore-cases from a sorus (Fig. 204, C, D), mount them in water, examine with , and note : (a) The stalk. (6) The spore-cases proper. Draw. (c) The partial ring of thick-walled cells enclosing the spore-case. (d) The spores. These should also be examined with Draw. The spores are scat- tered by the splitting open of the spore-case very dry, pulled apart by the elastic ring (Fig. 204, D). 364. The Gameto- phyte (Prothallium) and Sexual Reproduction. — Material for this study may be obtained by dusting spores of any desired species of fern over bits of brick or broken flower-pots or earth kept moist under a bell-glass. The spores of most genera are long- lived and germinate readily many months after they mature. They should be sown six weeks or more before the material is needed for class use. Germinating spores in all stages of development may also be found on flower-pots containing greenhouse species of fern,' particularly Adiantum. Mount some of the material, examine with , and note : (a) Several stages in the germination of spores. Draw. 1 Polypodlum is excellent material for the study of tlie sporangia. The minute structure of the vegetative portion of tlie feru is here Fig. 205. Prothallium of a Fern (PoZi/siictem). View of the under surface. gp, growing point; ar, archegonia; an, anther- idia; rh, rhizoids; s, region in which the spore germinated. (X about 8.). 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 Bergen, Joseph Y. (Joseph Young), 1851-1917. Boston, Ginn
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