Comparative Résumé of the Vascular Supply 
of the Perianth 
In minute flowers like those of Oberonia and in the 
flowers of the semi-saprophyte, Zeuwine, the vasculature 
is very poorly developed. As a result, the system is not 
attended by any secondary modifications (Fig. 6, B). In 
flowers like those of Vanilla, Coelogyne, ete., the mar- 
ginal traces of the adjacent perianth members lie close 
together (Fig. 6 C).. In Dendrobium, Bulbophyllum, 
A B G D E 
Fig. 6. A to E. Series of diagrams to illustrate the increasing com- 
plexity of the vascular supply of the perianth members, Only one- 
half of the flowers is shown; traces to the stamens and _ stigmas 
are not shown for the sake of avoiding confusion, 
Pholidota, Spathoglottis, etc., the marginal traces fuse to 
form an ‘‘arch’’ and from this point again separate out 
(Fig. 6 D). In Cymbidium and many members of the 
tribe Sarcanthinae, the marginal traces after forming an 
‘arch’? proceed in a fused condition for a considerable 
distance and then separate (Fig. 6 E). Often some of 
the marginal traces even enter the respective perianth 
member in the fused condition (see the marginal trace 
of the dorsal sepal in Fig. 6 E). 
It may also be noted that the main trace, DS, does not 
in general give rise to any of the marginal traces of the 
dorsal sepal. But when it does split up into the marginal 
traces, as in Cymbidium and some members of the Sar- 
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