PROTECTION OF BUDS IN THE TROPICS. 347 
that in Wormia triquetra, Rottb., an account of the latter may 
not be superfluous. 
The leaves of W. triquetra are elliptical, with conduplicate 
venation, and are supported by a petiole about half the length of 
the lamina. The stipules are ligulate, as long as the petiole and 
adnate to it, and so form wings on each of its sides, which extend 
from the base of the lamina to the insertion of the petiole upon 
the stem. The stipules, when young, arch over and cover up 
entirely the leaf which will be developed next in succession 
until it is ready to unfold, and so the young and unexpanded 
leaves are effectually protected. This will be better understood 
if we trace the life-history of one of the leaves. We will com- 
mence at the stage when the young leaf is entirely covered up 
(fig. 5, A, Pl. XLVII.); in this stage it is noticed that the petiole 
is swollen (fig. 5, A, a) on its upper surface ; and this swelling is 
caused by the stipules of the expanded leat arching over and 
covering up the next youngest leaf. At the stage a little more 
advanced we see the young leaf, still unexpanded, just emerging 
from the covering stipules (fig. 5, B). The young leaf in this 
condition is nearly as long as the ‘petiole of the leaf which was 
developed immediately before it, so that the young leaf is entirely 
covered over. The next stage (fig. 5, C) shows the leaf after it 
has completely emerged from the stipules and is just beginning 
to expand. The leaf is now strong enough to resist the ordinary 
external conditions, and soon attains its full development. Its 
petiole (fig. 5, C), it will be noticed, has a similar swelling to the 
one already described ; this is caused in the same manner by its 
stipules covering over the next youngest leaf, and so on. Thus 
the same story is repeated for every leaf, and each leaf in turn 
has the benefit of stipular protection from an older leaf. 
The history of the stipules after they have served as protecting 
ans is interesting. At first, that is while they are covering over 
a young leaf, they are green; but when the leaf has emerged 
from them, they soon turn brown and wither, and are of no further 
use to the plant. The stipules, therefore, are cast off, the sepa- 
ration of petiole from stipule commencing at the base of the 
petiole and proceeding to the lamina (Pl. XLVII. fig. 5, B and D). 
This separation proceeds until the stipules are completely 
separated from the petiole; they then fall off, and consequently 
two long scars are left on each side of the petiole, showing where 
the stipules had been. 
LINN. JOURN.—BOTANY, VOL. XXVIII. 
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