. The structure and development of mosses and ferns (Archegoniatae). er-culum is very easily sep-arated from the dry cap-sule. Stomata, accordingto Schimper, always arepresent, sometimes ingreat numbers; but Hab-erlandt ((4), p. 475 )>states that these are al-ways rudimentary, andhe regards them as re-duced forms. No seta isformed, but its place istaken physiologically bythe upper part of the axisof the archegonial branch,which grows Up beyondthe perichaetium, carryingthe ripe sporogonium atits top (Fig. 91, E). Theupper part of this pseu-dopodium is much en-larged, and a section through it
. The structure and development of mosses and ferns (Archegoniatae). er-culum is very easily sep-arated from the dry cap-sule. Stomata, accordingto Schimper, always arepresent, sometimes ingreat numbers; but Hab-erlandt ((4), p. 475 )>states that these are al-ways rudimentary, andhe regards them as re-duced forms. No seta isformed, but its place istaken physiologically bythe upper part of the axisof the archegonial branch,which grows Up beyondthe perichaetium, carryingthe ripe sporogonium atits top (Fig. 91, E). Theupper part of this pseu-dopodium is much en-larged, and a section through it shows the bulbous foot of thecapsule occupying nearly the whole space inside it. The ripecapsule breaks through the overlying calyptra, the upper partof which is carried up somewhat as in the higher Mosses, whilethe basal part together with the upper part of the pseudopodiumforms the Vaginula. The disorganised contents of the canal cells, which areusually ejected from the archegonium, in Sphagnum remain ina large measure in the central cavity, and on removing the. Fig. 93.—Median longitudinal section of anearly ripe sporogonium of S. acutifoli-urn, X24; ps, pseudopodium; sp, spores;col, columella (after Waldner). V. MOSSES (MUSCI): SPHAGNALES—ANDREJEALES i8i young embryo from the venter of the archegonium, this muci-laginous mass adheres to it and forms a more or less completeenvelope about it, in which are often found the remains ofspermatozoids. The species of Sphagmim are either monoecious or dirjecious,but in no cases do archegonia and antheridia ocair upon thesame branch. The Andre^ales The second order of the Mosses includes only the smallgenus Andrecoa, rock-inhabiting Mosses of small size and dark
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Keywords: ., bookauthorcampbelldouglashought, bookcentury1900, bookdecade1910
