7 
of Marattia Douglasii , Baker. 
and from the uppermost the neck. Compared with the 
homosporous leptosporangiate ferns, the most striking dif- 
ferences are the short neck and the broad canal-cells. The 
neck projects but little and contains only three or four 
cells in each row. The egg-cell is small and the ventral 
canal-cell extraordinarily large. Jonkman 1 has shown that 
the neck canal-cell is frequently divided, and Farmer 2 has 
confirmed this as a common but not invariable occurrence 
in Angiopteris. In Marattia Douglasii , it does not ordinarily 
occur, although the division of the nucleus seems always to 
take place. While a trace of a wall was not infrequent, in no 
case was a firm wall, such as Jonkman showed, to be seen. 
As the number of perfect sections of mature archegonia was 
small, however, it is not at all unlikely that in this species, 
too, a complete division of the neck-cell may often occur. 
Of the Filicineae, Isoetes comes nearest to Marattia , from 
which it differs mainly in the larger size of the egg and the 
absence of the basal cell of the archegonium. 
The study of the archegonium of Marattia has suggested 
a possible explanation of the origin of the archegonium of 
the Pteridophytes which is so constant in its structure, and 
seems to differ so radically from the bryophytic type. All of 
the eusporangiate Pteridophytes are characterized by the 
short neck of the archegonium, while the leptosporangiate 
ferns have as a rule a relatively long neck: but in all, the base 
of the archegonium is never free. Among the Bryophytes, 
with the single exception of the Anthoceroteae, the young 
archegonium is entirely free and the first divisions are always 
the same. In the Anthoceroteae, the archegonium is even 
more completely sunk in the thallus than in any Pteridophyte. 
It was shown by Janczewski 3 and Leitgeb 4 , however, that 
the archegonium of Anthoceros does not differ so much from 
that of the other Liverworts as has been supposed, and that 
1 Loc. cit. p. 2 1 6. 
2 Loc. cit. p. 266. 
3 Janczewski, Bot. Zeitung, 1872. 
4 Leitgeb, Untersuchungen iiber die Lebermoose, Heft V, pp. 3, 4. 
