. Contributions from the Osborn Botanical Laboratory. Plants. CHILEAN SPECIES OF METZGERIA. 311 develop new eostae (Fig. 9, A), sometimes retaining them as long as growth continues and sometimes losing them before growth is brought to an end. It will be seen from this account that the gemmipar- ous branches exhibit a wide range of variability. The first gemmae to be pro- duced are marginal and arise in acropetal succession, every margi- nal cell in extreme cases giving rise to a gemma. If the gemmi- parous branch shows the more specialized features described above, some of the later gemmae may
. Contributions from the Osborn Botanical Laboratory. Plants. CHILEAN SPECIES OF METZGERIA. 311 develop new eostae (Fig. 9, A), sometimes retaining them as long as growth continues and sometimes losing them before growth is brought to an end. It will be seen from this account that the gemmipar- ous branches exhibit a wide range of variability. The first gemmae to be pro- duced are marginal and arise in acropetal succession, every margi- nal cell in extreme cases giving rise to a gemma. If the gemmi- parous branch shows the more specialized features described above, some of the later gemmae may be given off dorsally from the submarginal alar cells and perhaps also from the cortical cells of the costa both dorsally and ventrally, the acropetal succession in such cases not persisting. In instances of extreme production the crowded gemmae extending in all directions almost conceal the tip of the slender gemmiparous branch, although even then the apical cell of the branch can us- ually be clearly distinguished. At the time of separation the gemmae vary considerably in size, but an average example measures about mm. and is five cells across. It is oblong in out- line and strongly convex, the. Fig. 9. Metzgeria violacea Dumort. (Ach.) A, B. Gemmiparous branches, ven- tral view, X 50. C. Gemma about ready to separate, X 100. D. Germi- nating gemma, X 100. A was drawn from an unnumbered specimen labelled whole margin (including the single M. angusta and collected at Punta apical cell and the indistinct stalk) i^^Z^t^^'Jl^A^t being revolute (Fig. 9, C). On each side three or four short rudi- ments of marginal hairs can be distinguished; these normally arise between every two marginal cells and may be borne singly or (more rarely) in pairs. Otherwise the gemmae show no cell-differentiation and are unistratose throughout. men collected at the same locality by Thaxter, No. Please note that these images are extracted from scanned page images that may have been digi
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