Some preliminary Experiments on Physiology of Charophyta.1

The Charophyta have been frequently the object of study of the appearance of streaming of protoplasm, yet the fundamental questions regarding their physiology remained almost wholly untouched. The Charophyta, biologically, represent a fairly devel­ oped type among the Thallophyta. Regarding nutrition they remind us of higher plants because of the presence of rhizoids. According to Bi e r b e r g ’s investigations the rhizoids not only perform the function of fixations, but also the main function of nutrition. The nutritive materials are — to our knowledge — not yet analysed. Occasional observations only have been made so far, namely: that the growth of Charophyta varies in different soils (M ig u la , E rn s t) . We know just as little about the external factors of the growth of the Charophyta such as light and temperature. Only lately K a r l Fug investigated the activity of light. From observation in nature we know the great influence1 of light upon the growth and fructification of Charophyta. . The few investigations on Charophyta led to some preliminary fundamental experiments with Charophyta. The following questions were put: 1. How will Charophyta absorbe nutritive materials? Are the rhizoids the only organs of absorbtion or is the surface of thallus performing the same function? 2. What is the growth of Charophyta in differing soils? 3. What is the relation of the Charophyta to the light factor? In what way does light influence the growth of the vege­ tative organs and their propagation? 4. What is1 the/ relation of the Charophyta to mineral nutrition? Which mineral nutritive material is indispensable to Charo­ phyta?