361 
growth will occur at an older stage, but it is very probable, the 
position of the cambium-like pericycle agreeing closely with 
that of B. lunaria. The cork formation occurs in the same places 
as in B. obliquum. 
The big cotyledon (Fig. 33) shows two separate exarch xylems, 
and in contrast with B. obliquum, no distinct phloem could be 
traced. Like the other Botrychia, there is no endodermis. The 
most conspicuous features of the cotyledon are the tannin cells. 
They make their appearance at a rather young stage ; (see Fig. 38; 
Fig. 33) as the third leaf becomes conspicuous. They are con- 
fined to two regions only: 
1. The epidermis. 
2. The layers surrounding the stele and more or less corre- 
sponding with the endodermis (West (42) describes a mucilage 
duct in the endodermis of Marattia). 
In longitudinal sections the tannin cells appear as very long, 
worm-like structures. Their contents are granular and stain 
from light green to dark brown with Bismarck brown. With 
iron chloride or copper bichromate, strong tannin reactions 
were obtained, much stronger as in the case of B. virginianum. 
It seems to point to a relation with Helminthostachys, which, 
for a representative of the “lunaria”’ group, is very improbable. 
The plants were too young to show either a lysigenous or schizo- 
genous origin of tannin ducts, as occurs in the WMarattiaceae 
(West 42). It is doubtful if the cells in B. simplex will ever fuse 
or pour their contents into cellular spaces. In longitudinal 
sections, the transverse walls are sometimes very difficult to 
trace. Ît was therefore impossible to make out if in B simplex 
the tannin ducts occur in a new form: the tannin vessel, 
although the existence of these vessels is probable. 
Conclusions. 
The development of Botrychium simplex shows clearly its 
close affinity to B. lunaria, the only essential difference being 
the occurrence of tannin cells (or vessels) in thre former. Othe 
