. Die Eusporangiatae; die vergleichende Morphologie der Ophioglossaceae und Marattiaceae. ; Ophioglossaceae Marattiaceae. 20 DIE OPHIOGLOSSALES obwohl man im letzteren ein Paar antheridia sind fast immer entwickelt, bevor die Arche - ponia angezeigt werden. . ,. ,,, Die In der männlichen prothallium der basalen "vegetativen Teil ist relativ klein und oft unregelmäßig gelappt, diesen Vorsprung nicht von der Art der wahren Zweige, sondern lediglich das Ergebnis der ungleichen Wachstum. Die Weibliche gametophyte (Abb. lo) hat die basale Region relativ größer und ist sogar noch unregelmäßig in Form als die Männchen, während die fruchtbaren

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. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. 20 THE OPHIOGLOSSALES although in the latter a few antheridia are almost always developed before the arche- ponia appear. . , . , , , In the male prothallium the basal "vegetative portion is relatively small and often is irregularly lobed, these lobes being not of the nature of true branches, but merely the result of unequal growth. The female gametophyte (fig. lo) has the basal region relatively larger and is even more irregular in form than the male, while the fertile region is shorter and wider. Some of the more elongated types of the male gametophyte are quite similar to the simple prothallium of Ophioglossum moluccanum. As in the other genera, the endophytic fungus is always present and occupies much the same position as in Botrchium. Lang found that the growth is due to the activity of a single apical cell having the form of a four-sided pyramid, much like that found in Ophioglossum pendulum. The lateral segments divide by periclinal walls, and from the superficial cells thus formed originates the layer of tissue from which the sexual organs arise. The inner cells contribute to the axial tissue of the gametophyte. The antheridia in the male plants are evenly distributed about the periphery, so that in cross-section they form a nearly uniform circle. The axial tissue, especially in the male prothallium, has the cells much elongated, and Lang thinks they are useful in the conduction of plastic material from the basal region of the prothallium to the growing point. The outer part of the basal region consists of two or three layers of somewhat flattened cells, which, like the corresponding tissue in Botrychium, are free from the endophyte. From some of these superficial cells there are developed unicellular, elongated rhizoids, with markedly cutinized walls. This cutinization extends to the outer walls of the superficial cells, while the in

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