. Journal of the Straits Branch of the Royal Asiatic Society. />Qtr- Fips. 9 and 10. Two cases in which the leaves of the whorl diff red fromeach other in very little. leaves are in a whorl of four. In both genera with the next leaf, thealternate condition sets in which persists through life. There is no important difference in the microscopic structureof the petiole of a leaf of the whorl and of the fifth leaf: bothin section about the middle exhibit (see fig. 11) a ring ofnormal cortex enclosing a ring of sclerenchyma within which isphloem and xyleim and an included bundle with the xylem
. Journal of the Straits Branch of the Royal Asiatic Society. />Qtr- Fips. 9 and 10. Two cases in which the leaves of the whorl diff red fromeach other in very little. leaves are in a whorl of four. In both genera with the next leaf, thealternate condition sets in which persists through life. There is no important difference in the microscopic structureof the petiole of a leaf of the whorl and of the fifth leaf: bothin section about the middle exhibit (see fig. 11) a ring ofnormal cortex enclosing a ring of sclerenchyma within which isphloem and xyleim and an included bundle with the xylem towardsthe face of the leaf as drawn. Associated with the largest xylemvessels are resin ducts to the number of five. Close under the blade,. Fig. 11. Petiole in transverse , sclerenchyma: and r. Canal, resin canal. H. A. Soc, No. 75, 1917. 49 NOTES ON DI TEROCARPS, through that part of the petiole which is a pulvinus, the scleren-chyma is wanting, while the ring of bundles is a little irregularand the cortex is thicker. Such changes are of course connectedwith the mobility required of the pulvinus: they take place in thepetioles of the whorl in the same way as in the fifth leaf. Andthere is nothing further peculiar about these whorled leaves beyondthe circumstances of their association and their inequality. Compared with the adult leaves, they are of course muchsmaller, up to cm. long by cm. wide, and the vascular ele-ments in the petiole, etc., in the large leaves are altered by the in-creased number of groups of larger xylem vessels in the ring, andby the space within this ring being completely occupied by a com-plex of bundles with much sclerenchyma. At the pulvinus thesclerenchyma is interrupted,
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