. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. 210 ORIGIN AND RELATIONSHIPS OF THE EUSPORANGIATAE. The large, green sporophyte, however (fig. 190, A, sp), never attains complete inde- pendence, as no proper root is developed and it is dependent for its water supply upon the gametophyte. In all of the Eusporangiates, the embryo is much later in developing its organs than in the Leptosporangiates, and thus resembles the Bryophytes; moreover, the embryo reaches a very much larger size before it attains its independence. Eve
. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. 210 ORIGIN AND RELATIONSHIPS OF THE EUSPORANGIATAE. The large, green sporophyte, however (fig. 190, A, sp), never attains complete inde- pendence, as no proper root is developed and it is dependent for its water supply upon the gametophyte. In all of the Eusporangiates, the embryo is much later in developing its organs than in the 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. 190. A. Gametophyte of Anthoccros sp. with the large sporophyte, sp, attached to it. Upper part of sporophyte is sph't into valves which allow the escape of spores. B, C. Two gametophytes of Marattia douglasii, with attached sporophyte. Sporophyte emerges upon upper side of gametophyte, very much as in Anthoceros, 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 be 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 Pteridophytes. In Anthoceros, however, the Fig. 191. Diagrams which show the similarity in form of the very young sporophyte in Anthoceros, A, and Ophioglossum, B. In the former the u
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