. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. 132 THE MARATTIALES this is not ordinarily the case. In one instance in this species I observed a division by a vertical wall, so that two neck canal cells were formed, placed side by side, in a way recalling very strongly the division of the neck canal cell described by Jeffrey in certain species of Equisetum (Jeffrey 2). The central cell is divided again by a hori- zontal wall into two nearly equal cells, the lower one being the egg, the upper one the ventral canal cell. T
. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. 132 THE MARATTIALES this is not ordinarily the case. In one instance in this species I observed a division by a vertical wall, so that two neck canal cells were formed, placed side by side, in a way recalling very strongly the division of the neck canal cell described by Jeffrey in certain species of Equisetum (Jeffrey 2). The central cell is divided again by a hori- zontal wall into two nearly equal cells, the lower one being the egg, the upper one the ventral canal cell. The mature egg is nearly elliptical in form, the upper third being almost homogeneous and quite colorless, forming the so-called receptive spot. The nucleus is of moderate size and does not stain very strongly. The archegonium of Angiopteris closely resembles that oi Marattta, but is perhaps somewhat narrower (fig. loi). Jonkmann figures the archegonium of M. cicutcefolia, which shows that this species also is, in the relative size of the canal and neck cells, very much like Angi- opteris. Farmer thought that a basal cell was usually, if not always, present, and my own studies tend to confirm : Fig. T02. Archegonia of X'suZ/uijia. X210. i, basal cell; d, egg; », ventral canal cell; n. c, neck canal cell. In Kaulfussia (fig. 102) the archegonia form, as a rule, only after the antheridia have ceased to develop. Compared with the other Marattiaceze they are decidedly large, and in this respect Kaulfussia approaches Ophioglossum. Like the mother cell of the antheridium, there is a good deal of variation in the width of the young archegonium in Kaulfussia. Some of the narrower types recall the archegonium of Anthoceros and emphasize the resemblances between the archegonium of the Anthocerotaceae and the eusporangiate ferns. The neck of the archegonium is very short, each of the four original neck cells often dividing only once, so that there may be but two cells to each of
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