Stem of A ngiopteris evecta. 519 
roots of Angiopteris , but in connexion with these cases it 
may be of interest to mention that Mr. Seward has noticed 
apparent dichotomy in a petiole of an Angiopteris plant in 
the Botanic Garden at Leipzig. 
The origin of the roots from the vascular strands of the 
stem has not been worked out, but it may be suggested that 
there is some relation between the roots and the central 
protoxylem in the stem stele. Casual sections showing the 
origin of the roots confirm the statement giveji by Mettenius 
of the presence of short, irregularly-shaped scalariform 
tracheides at the junction of the root and the stem-stele 1 . 
The apices of the roots found on the plant under investi¬ 
gation were either absent, or in a too much decayed condition 
to afford any information as to their structure. My investi¬ 
gations into the root-apices obtained from the plant in the 
Cambridge Botanic Garden are confirmatory, as far as they 
go, of the views expressed in Koch’s paper. 
In the stouter air-roots a gap occupies the general position 
of the apical cells, and growth is carried on by the tissue of 
meristematic cells which surround the cavity. The gap, 
which originates near the apex by the disorganization of the 
large apical cells, persists for a considerable distance in 
the centre of the root-stele. 
In somewhat smaller roots, several large cells are present 
at the junction of the root-cap tissue with that of the root 
proper, but it was not possible to determine their actual 
relation to each other. In the small branch-roots growth 
is apparently carried on by means of one apical cell, as 
described by Holle; this method of growth is indicated by 
the arrangement of the cells in the apical region, as seen in 
transverse section, in roughly concentric circles, but its exis¬ 
tence can hardly be said to be definitely proved. 
III. Leaf. 
There is no intention in the present paper to give any 
detailed account of the leaves of Angiopteris , but a few points 
Mettenius (’64), p. 519 . 
