476 
under the pit connecting it with the central cell (comp. Kyrın 1923 fig. 62 a) and 
this pit is later to be found near the upper end of the central cell. The lowermost 
cell resulting from this division is at first not connected with the central cell by a pit, 
but such a con- 
nection must lat- 
er be establish- 
ed for in a more 
advanced stage 
the lower end of 
the central cell 
is also connect- 
ed with the sur- 
rounding cells by 
pits (fig. 439 A, 
C). The pericen- 
tral cells are con- 
nected longitudi- 
nallyby multiple, 
usually three pits 
of which all or 
at least two are 
secondary. 
The lateral 
veins of the first 
order arise in the 
upper border of 
the primary seg- 
ments. Lateral 
veins of the se- 
cond order are 
given off from’ 
the lower side 
of the primary 
Fig. 438. 
Delesseria sanguinea. A, growing point of young leaf; the division of the apical cell has 
begun. B, lateral part of the same leaf; the intercalary division walls are marked with ones; only near 
an =. C, marginal portion of frond at a longer distance from the top, showing the second- 
ary pits (=). D, young adventitious shoot given off from a mid-rib. A, B 560:1. D 200:1. the margin of the 
leaf small veins 
may also sometimes project from the upper side. Veins of the third order may be met 
with and anastomoses of the veins may occur near the border. The branching of 
the veins is wrongly represented in Flora Dan. pl. 349. 
The leaves do not normally branch, and branched leaves do not seem to have 
been mentioned in the literature. I have, however, observed some cases of branched 
leaves; as they have been met with in three different places, branched leaves may 
