Stem of Angiopteris evecta. 501 
apical region, but is not necessary for the production of the 
root tissues. This is shown by the fact that at some little 
distance from the root-tip a gap, due to the disorganization 
of the constituent cells, appears in the midst of the cell 
complex, and growth is carried on by small meristematic 
cells which surround the cavity. 
Turning now from the consideration of literature dealing 
exclusively with the root, we find an account by De Bary of 
a young stem of Angiopteris evecta. This showed a typical 
bundle-tube with wide foliar gaps, from the lateral margins 
of which two steles arise, ascend obliquely through the cortex, 
at the same time undergoing division, and then pass off into 
the leaves. 
Particular points of interest, such as the structure and 
origin of the mucilage canals, and of the pits, or ‘ lenticels,’ on 
the leaf-bases and stipules, are discussed in papers by Brebner 1 , 
Potonie 2 , Hannig 3 , and others. The curious intercellular 
network of rodlets, due to outgrowths from the walls of the 
cells, is characteristic of the parenchymatous tissues of 
the Marattiaceae, and is described by Luerssen 4 , Schenck 5 , 
Poirault 6 , and Kuhn 7 . 
External Features. 
In a description of the external features of Angiopteris 
evecta , no strict line of demarcation can be drawn between 
the stem proper and the massive leaf-bases with which it is 
completely covered. 
The axis, which is obliquely ascending, ends at the base 
in a naked blunt cone (Fig. 1), but this region shows un¬ 
doubted marks of erosion, and it is probable that it was more 
or less covered with leaf-bases similar to those found higher 
up on the stem. After the removal of the leaves the general 
form of the stem is seen to be obconical, and in its older parts 
distinct dorsiventrality of structure is presented. 
1 Brebner (’95). 2 Potonie (’81). 8 Hannig (’98). 
4 Luerssen (’73). 5 Schenck (’86). 6 Poirault (’93). 
7 Kiihn (’89). 
