Notes. 
H5 
an epiphyte which can grow as a terrestrial plant. In the Botanic Garden 
at Singapore a magnificent specimen of this gigantic orchid is growing 
planted in the soil. Its numerous stalks rise from the ground, and are 
densely beset with leaves. On approaching the plant one sees, under 
its shade, what resembles a low mass of dry whitened coarse grass. 
Closer inspection shows that this grass-like mass is really made up of 
numerous slender branched roots, which rise up out of the ground. 
Most of these roots have stopped growing and are white and stiff, but 
a few younger ones are less rigid, contain chlorophyll, and are light 
green in colour. Each of them takes origin from a thicker root which 
runs horizontally over, or beneath, the surface of the soil ; it ascends 
obliquely outwards (towards the light) or is quite erect, but its youngest 
portion is always vertical. At its base it gives off secondary branches 
in various directions, but towards its apex the secondary branches 
dwindle and become arranged in one plane — the plane at right angles 
to the direction of incidence of the strongest light, so that on approach- 
ing the plants these pinnately-arranged secondary roots attract imme- 
diate attention. The diminution in the size of the secondary roots 
towards the apex is so considerable that they are mere tiny knobs, 
smaller, in fact, than a pins head, even at some distance from the tip 
of the root. The larger basal secondary roots are directed towards 
the light, and give off tertiary branches, which are arranged in one 
plane just as are the smaller secondary roots. Each erect-growing 
root, as also its branches, only grows in length for a definite period, 
and then becomes hard and pointed. The bilateral nature of the 
portions of this root-system which are fully exposed to light, as denoted 
by the arrangement of the branches in one plane, recall Janczewski’s 1 
observations on the dorsi-ventral nature of many aerial orchid-roots. 
I have noted the same bilateral arrangement of the root-branches 
in the vertical roots of Cymbidium aloifolium growing in a pot ; but 
usually the upright roots of pot-specimens of this plant are more 
or less devoid of branches. 
But in the soil there is another system of roots quite different from 
that above described. These subterranean roots are thick and fleshy, 
and give off very few lateral roots. Immediately one of these roots 
ascends out of the soil it commences to branch, and in fact becomes 
one of the many aerial roots previously described. On the other hand, 
1 E. de Janczewski, Organisation dorsiventrale dans les Racines des Orchidees, 
Ann. d. sci. nat., Bot., 1885. 
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