THE INITIATION AND DEVELOPMENT OF RESIN DUCTS IN PINUS TABULAEFORMIS CARR.
油松树脂道的发生和发育研究

The structure and pattern of initiation and development of resin ducts in Plans tabulaeformis Carr. have be(?)n studied. It is found that the resin duets are formed sehizogenously, in all o(?)gans, except ovule, just as in other species of gymnospermus, but in ovule the resin duets are formed by lysis of some nucellar cells, pattern of initiation is sialiliar to that in most of angiospermus.The primary resin ducts in the root, stem, leave and the secondary resin ducts in the ray, resin duct initials form rosette, in the secondary root and stem, no rosette is formed.The structure of resin duets of the different organs is different. In the resin ducts of stem cortex, root and stem ray. scale, macrosporophyll and microsporophyll, sheath cells are living, whereas in those of the xylem of root, stem and needle, the sheath cells are dead ones with suherin wall. In addition, resin duets formed schizogenously are elogated structure, while resin ducts formed lysigenously are cyst-like structure.Tylosoid occurs at the later phase of resin ducts development in the heart-wood of stem, vascular strand of needle and scale, but they do not app- (?)ar in other organs.In this paper, difference of structure, initiation and development of resin ducts are analysed and discussed.