72 



the other M.irattiaceae. The older prothtilliii are relatively 

 broader (IM. Vll, Figs. 8, 5 and 6) and these usually bear archegonia. 

 Only in a few cases were young antheridia found upon pro- 

 thallia which boi'e archegonia. Whether this is always true 

 could not be decided from the small number of prothallia that 

 were available for study. 



The antheridia seemed to be formed first, and after these 

 have matured and discharged the spermatozoids, archegonia 

 arise in the same position with reference to the apex. Unlike 

 most ferns the walls of the empty antheridia do not become 

 discoloi'cd and they are easily overlooked. Careful examination 

 of the sections of the older prothallium will usually show the 

 empty antheridia, and it is probable that most of the prothallia 

 are proterandrous and not dioecious as might be supposed from 

 a casual examination. The margins of the large prothallia are 

 more or less irregularly lol)ed and are not unlike those of 

 O-'uniinda, but as in the other Marattiaceae, the wings are several 

 cells in thickness near the midrib and only at the extreme edge 

 do they become one cell thick. The full grown prothallia are 

 usually a centimetre or more in length and nearly as broad. 

 One very large one (PI. Vll, l^'ig. 7) liearing a young sporophyte 

 with two fully developed leaves was found, that measured nearly 

 two and one-half centimetres in length by one and three-fourths 

 in extreme width, and was also very thick. A second archegohial 

 cushion was present, (PL VII, Fig. 7 b 9) but whether this was due 

 to a forking of the original apex, such as is not uncommon 

 in }[((rattia and Angiopterisy was not determined, l)ut it is very 

 probal)le that such was the case. 



The rhiziods are stout with thick but quite colorless walls. 

 They often show apparently transverse septa and the end is 

 not infrequently divided (PI. VII, Figs. 8 and 9). So far as could be 

 determined from a somewhat hasty study of the rhizoids, these 

 septa are not formed as a result of true cell division and only 

 one nucleus could be seen. As this nucleus is large and con- 

 spicuous it seems likely that the formation of septa is not 

 accompanied by a division of the nucleus. Bkednkr describes 



