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This paper deals with a comparative observation on the processes of tissue differentia-tion of the newly formed bark in Eucommia ulmoides Oliv. when its trunk was wrapped upin a transparent or black sheet immedistely after girdling. After being enveloped, severallayers of the cells adjacent to the surface of the trunk formed calluses outward instead ofbeing suberized. Later, a cork cambium, about 3 to 5 layers of cells in thickness, appearednear the surface and the cells at its periphery were gradually suberized adn died. The new vascular cambium mny develop from the inner tissue of the immature xylemof the girdled trunk, whether being exposcd or wrapped up in a transparent plastic shect.The formation of the new cambium is about one week earlier in the trunk wrapped up ina transparent plastic sheet than that being completely exposed and two weeks earlier thanthat being wrapped up in a blach plastic sheet. The newly formed cambium possesses theproperty of a procambium in its early differentiation, forming spiral-thickened vessels in-ward and sieve eell-like elements outward. However, the constituent of the regenerated barkis about the same as that of the original.
This paper deals with a comparative observation on the processes of tissue differentiation-the newly formed bark in Eucommia ulmoides Oliv. When its trunk was wrapped up in a transparent or black sheet immedistely after girdling. After being wrapped, severallayers of the cells adjacent to the surface of the trunk formed calluses outward instead of being suberized. Later, a cork cambium, about 3 to 5 layers of cells in thickness, hadnear the surface and the cells at its periphery were gradually suberized adn died. The new vascular cambium mny develop from the inner tissue of the immature xylemof the girdled trunk, whether being exposedcd or wrapped up in a transparent plastic shect. formation of the new cambium is about one week earlier in the trunk wrapped up ina transparent plastic sheet than that being completely exposed and two weeks earlier thanthat being wrapped up in a blach plastic sheet. The newly formed cambium possesses the property of a procambium in its early diffe rentiation, forming spiral-thickened vessels in-ward and sieve eell-like elements outward. However, the constituent of the regenerated barkis about the same as that of the of the original.