Archangiopteris Henryi and other Marattiaceae . 261 
overlapping upper margins of the wings, which in this region are free from 
the leaf-base. The lower parts of the stipular wings (below the transverse 
commissure) enfold the next youngest leaf in front. During the unfolding 
of the leaf the transverse commissure gets torn across, as shown in Fig. 4. 
A comparison with the stipular appendages of Kaidfussia aesctdifolia (repre- 
sented somewhat diagram matically by Fig. 5) shows that the protective 
arrangements in this plant are on a slightly different plan. The upper free 
portions of the wings are here much larger, and suffice alone for the 
protection of their own leaf, while the transverse commissure joins the 
lower parts of the stipular wings in curving over and protecting the next 
youngest leaf in front. 
The Vascular System of the Stem. 
In order to observe the structure of the stem the larger leaf-bases 
were first of all removed and the rest of the specimen was then cut up into 
a series of transverse sections. Unfortunately the insertion of the vascular 
strands of the first two leaves upon those of the stem could not be 
satisfactorily followed out on account of the torn and ragged condition 
of the end of the specimen. The portion of the stem that extended beyond 
this point was very short and, being so near the meristematic tissues of the 
apex, it was not very suitable for anatomical purposes. The concrescence 
of the large leaf-bases with the axis of the stock causes the outline of the 
latter to be very irregular, and at the same time renders it almost im- 
possible to draw any definite limit between the ground-tissue of the stem 
itself and that of the adhering leaf-bases. The vascular system of the stem 
consists of a single dictyostelic ring of two to four small meristeles more 
or less oval in section. In addition there is usually a small vascular strand 
lying in the central ground-tissue enclosed by this ring (int. s. in Fig. 6 ). 
This internal strand may, however, sometimes be absent (Fig. 7). A 
varying number of entering leaf-traces occur at different levels in the 
peripheral ground-tissue, which is also traversed by a number of roots 
passing downwards and outwards. The meristeles of the ring anasto- 
mose with each other in a somewhat irregular manner ; anastomoses 
being present other than those which close the leaf-gaps. In one region 
the meristeles all fuse up to form a single large curved strand. 
The small internal strand runs free in the central ground-tissue through 
the greater part of its course, but from time to time it approaches the 
dictyostelic ring and fuses with those meristeles that are about to close 
up the upper ends of a leaf-gap. Soon after it separates off again and 
passes on across the central ground-tissue to the next leaf-gap above. 
In one region the central strand ended blindly in the downward direction 
and for some distance below this point the dictyostelic ring alone was 
