. Carnegie Institution of Washington publication. 210 ORIGIN AM) RELATIONSHIPS of nil I I M'oK WGIATAE I lu large, green sporophyte, however (fig, 190, A,.«/>), never attains complete inde- pendence, as no proper root is developed and it is dependent for its water supply upon tin gametophyte. In all of the Eusporangiates, the- embryo is much latei in developing its organs than in tin- Leptosporangiates, and thus resembles the Bryophytes; moreover, the embryo reaches a very much larger size before it attains its independence. Even after the young sporophyte has developed several roots and le
. Carnegie Institution of Washington publication. 210 ORIGIN AM) RELATIONSHIPS of nil I I M'oK WGIATAE I lu large, green sporophyte, however (fig, 190, A,.«/>), never attains complete inde- pendence, as no proper root is developed and it is dependent for its water supply upon tin gametophyte. In all of the Eusporangiates, the- embryo is much latei in developing its organs than in tin- Leptosporangiates, and thus resembles the Bryophytes; moreover, the embryo reaches a very much larger size before it attains its independence. Even after the young sporophyte has developed several roots and leaves, it may still Fig. 110. A. Gametophyte of Anthoctroi sp. with the large porophyte, sp, attached to it. Uppei part .-lit into which allow the escape of spores. B, C. Two gametophytes of Marattia ilouglasit. with attached sporophyte. Sporophyte emerges upon upper side of gametophyte, very much as in Jnthoceros, but a root, r, is developed which penetrates lower side of gametophyte and connects the young sporophyte with the earth. g, gametophyte; sp, sporophyte; /, first leaf; r, primary root. maintain its connection with the gametophyte and he to a certain extent dependent upon it in a way which forcibly recalls the relation of gametophyte and sporophyte in the mosses. This condition, which furnishes a very strong argument in favor of the primitive nature of the Eusporangiates when compared with the Leptosporan- giates, is especially pronounced among the Ophioglossaceae, where it may even go so far that spores are developed before the connection of gametophyte and sporophyte is finally sundered. In the true mosses the sporophyte is exceedingly specialized and shows but a very remote resemblance to that of the Ptei idophytes. In Anthoccros, however, the. 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 wo
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Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1911
