. The structure and development of mosses and ferns (Archegoniatae). pecies of Osmunda and Todea inthe better development of the endodermis, and in having thepericycle of but one or two layers. The vascular cylinder of theroot is typically diarch like that of the Polypodiaceae, but ex-ceptionally (Faull (i), p. 22), it may be triarch. The roots arise regularly, two at the base of each leaf(Lachmann (7), p. 118), and their bundles connect with thoseof the stem near the bottom of the elongated foliar gap in itsvascular cylinder. THE HOMOSPOROUS LEPTOSPORANGIATJE 36= The Sporangium The sporangia
. The structure and development of mosses and ferns (Archegoniatae). pecies of Osmunda and Todea inthe better development of the endodermis, and in having thepericycle of but one or two layers. The vascular cylinder of theroot is typically diarch like that of the Polypodiaceae, but ex-ceptionally (Faull (i), p. 22), it may be triarch. The roots arise regularly, two at the base of each leaf(Lachmann (7), p. 118), and their bundles connect with thoseof the stem near the bottom of the elongated foliar gap in itsvascular cylinder. THE HOMOSPOROUS LEPTOSPORANGIATJE 36= The Sporangium The sporangia in Osnmnda are produced upon sporophyllsthat closely resemble those of Bofryclihun or Helminthostachys,but in Todea they occur upon the backs of the leaves, as inmost Ferns. In structure and development they are intermedi-ate between the true leptosporangiate type and the eusporangi-ate. So far as they have been investigated they all correspondvery closely. The origin of the sporangia is almost identicalwith that in Botrvchium, and more than one cell may take part.
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Keywords: ., bookauthorcampbelldouglashought, bookcentury1900, bookdecade1910
