of Marattia Douglasii , Baker. i 7 
The very massive, long-lived prothallium of Marattia , and 
especially the fact that the prothallium remains active long 
after the sporophyte becomes independent, seem conclusive 
evidence of the primitive nature of the former. The long 
dependence of the embryo also, and the late development of 
the root, point to the same thing. In both of these particulars 
Marattia surpasses all other Pteridophytes known. It is quite 
possible that the Ophioglosseae may show similar peculiarities, 
but they are too imperfectly known to determine this. The 
peculiar position of the embryo, also, points to the not very 
remote derivation of these plants from those in which the 
archegonium was upon the upper surface of the prothallium, 
as, in all other forms where the archegonium is upon the lower 
side, the basal wall has shifted in such a way as to bring 
the cotyledon next to the neck of the archegonium and it 
emerges below. In all of these particulars, as well as in the 
structure of the archegonium, Marattia comes nearest to the 
Liverworts of any Pteridophytes yet examined, and of the 
Liverworts, the Anthoceroteae are undoubtedly the ones to 
which the resemblance is most marked. This peculiar group 
has been the subject of repeated exhaustive researches, and 
yet some of the most striking points of resemblance be- 
tween them and the Pteridophytes seem to have been 
overlooked. The remarkable correspondence between the 
archegonium of Anthoceros and that of Marattia has already 
been referred to, and gives a possible explanation of the 
origin of the pteridophytic archegonium from that of the 
Bryophytes. The antheridium, however, is not so easily 
explained. All of the eusporangiate forms have the antheri- 
dium also sunk in the prothallium, and its origin in Anthoceros 
is still an open question 1 : but in the latter, whether endogenous 
in origin or not, the mature antheridium is closely like that of 
the other Liverworts. There is, however, a close resemblance 
between the antheridium of Marattia and that of the other 
1 Since writing the above my attention has been called to a paper by M. Waldner 
(Die Entwickelung des Antheridiums von Anthoceros, Sitzungsb. der Kais. Akad. 
der Wiss. LXXXV, Wien, 1887), but unfortunately the paper was not accessible. 
C 
