OSMOTIC VALUES OF CELL-SAP IN CONOCEPHALUS CONICUS(L.)NECKER

Abstract

Osmotic values of the cell-sap in Conocephalus conicus were investigated by the plasmolysis method. As to the seasonal fluctuation, the following were recognized(Fig. 1) : The value descends promptly in April ; this seems to represent dehardening of the plant itself caused by temperature ascension. It is low in summer and becomes higher towards winter when the plant results in its hardening state by temperature descension. But it is exceptionally very high in August especially in the newest branches of thalli which grow somewhat apart from the ground ; this is perhaps caused by dryness of the environment because the weather is very dry in this month in our district. In the isolated thallus, the value is the lowest at the growing point, higher at more basal (older) parts. higher at marginal parts than median ones (Fig. 2) and higher at the upper surface than at the lower one (Table 1). In view of these facts, this liverwort seems to belong to the endohydric plants as suggested by H. BUCH^2). To our interest, the disk of the archegoniophore and thallus are almost isotonic with each other even when the former is held on the slender and long (up to about 7 cm in length) stalk in which the osmotic value is low as about 1/2 as those in the thallus and the disk (Fig. 3). These facts perhaps prove that the transpiration stream does not occur through the stalk. : The daily march of the osmotic values shows fair rhythmicity in September, but little fluctuation in winter even if the measurement is carried out on fine days(Fig. 4).