iS 7 
Different Types of Angiospermic Vessels. 
similar conditions have been observed in Tropaeolum (Fig. 9), and in Pelar¬ 
gonium paelargium collected at Cape Town. From these figures it seems 
clear that small perforations are fusing irregularly and producing large 
simple perforations. In many vessels in the region where this fusion 
is proceeding the perforations are scalariform or nearly so (Fig. 8), while in 
Fig. 8. a-f. Scalariform-reticulate perfora- Fig. 9. a and B. Loss of reticulations in 
tions and their fusion in Cydonia. vessels of Tropaeolum. 
Fig. 10. A-C. Perforations in Epacris 
coriacea. 
Fig. 11. a and b. Perforations in 
Epacris coriacea. 
other vessels the reticulate condition which frequently accompanies the 
scalariform is evident. Such fusions are relatively rare and are usually 
found in herbs. 
Still another type approaching a net is figured by Solereder ( 4 ) for 
Epacris. In this case there are peculiar clusters of perforations as shown 
in Fig. io, A. Careful examination of many vessels shows, however, that 
these are really due to scalariform bars inclined at different angles on the 
two sides of the wall as seen in Fig. io, B and C, and Fig. n, A. Frequently 
the bars on one side are larger and farther apart than those on the other 
side. Sometimes the finer bars can be traced right across the larger ones, 
but in other preparations they cannot be so traced. In some cases (Fig. 11, b) 
the bars on one side disappear, while those on the other side remain. 
