1 6 Campbell, — Observations on the Development 
The first leaf is destitute of the stipules characteristic of 
the leaves of the older plants, but the third leaf has them 
well developed. The second root arises close to the base 
of the second leaf and at first there seems to be a root 
formed at the base of each of the young leaves. In the older 
sporophyte the roots are more numerous. 
It has been shown that in the earliest stages the divisions of 
the embryo of Marattia correspond with those of the other 
Pteridophytes and that the position of the primary organs is 
the same with reference to the basal wall, but that their 
position with reference to the archegonium is different. In 
all other forms the cotyledon arises from one of the quadrants 
next to the neck of the archegonium, while the reverse obtains 
here. Probably the transverse basal wall is the primitive 
condition, as it is found in all Eusporangiatae examined and 
is also found in nearly all Bryophytes. The different arrange- 
ment in most Leptosporangiatae is probably due largely to 
the shifting of the position of the archegonium. Of other 
ferns we have seen that, next to Angiopteris with which 
Marattia closely agrees, Osmunda most nearly resembles it. 
Isoetes, while showing a resemblance in the early divisions of 
the embryo, differs very much, not only from the Marattiaceae, 
but all other Pteridophytes, in the origin of the stem-apex, 
which resembles closely that of some Monocotyledons. With 
the higher Leptosporangiatae the embryo of Marattia has 
little in common beyond the first divisions. 
Conclusions. 
From a careful study of the facts presented here, as well 
as the other recent contributions to our knowledge of the 
Marattiaceae, there seems to be no reason to modify the 
opinion already several times expressed, of the primitive 
nature of the eusporangiate Pteridophytes. These, however, as 
well as a careful study of several species of Anthoceros , will 
enable us to understand somewhat more closely the position 
of the Marattiaceae in the system, and the origin of the 
Eusporangiatae from the Bryophytes. 
