230 
A. G. Tansley. 
The vascular supply of the pinnae is worthy of note. Each 
pinna receives two strands from the rachis. One of these is large 
and comes from the side of the curve. The other is small and 
comes from the incurved end of the terminal strand on the same 
side, travelling outwards along the inner side of the curve (Fig. 72, E) 
to pass out to the pinna. Similar phenomena have been found in 
Fig. 74. Datura simplicifolia. Series of transverse sections of vascular 
system of older stem, with perforated dictyostelic structure, illustrating 
passage of internal strands into pith, where they fuse into one. Letters as in 
Fig. 73. From Brcbner. 
the other genera of Marattiacese. The effect of this arrangement 
is to supply each pinna with water partly through a channel derived 
from the terminal strand, which has itself received a branch derived 
from the strands of the main abaxial curve. This arrangement is to 
some extent parallel with that of the internal strands of the stem, 
the supply of the pinna bearing somewhat the same relation to the 
