Sixteen strains of moulds were examined on the point of cerophilic growth and tonophilic. (1) Cultures were performed on hypertonic growth media containing varied concentrations of sodium chloride. The tested mould strains were divided into three groups, namely “steno-”. “eury-” and “non-halophilic” forms. (2) Cultures were performed under varied atmospheric humidity. The results obtained are shown in Figure 1 and the results of this set of experiments are summarized in Table 2, together with those described in the previous section. (3) In order to elucidate whether the tonophilic nature of mould depends on its nutritional condition, another series of experiments was performed. The results obtained were shown in Table 3 and 4.
In this paper the authors tried some fundamental investigations on the 14C-method for measuring primary production in the lake in comparison with the O2-method. From the results obtained it was confirmed that the 14C-method is useful for the measurement of the net photosynthesis and the exposure to light for the measurement should not exceed half a day even though in case of the 14C-method. In general, dark fixation of CO2 in lake is low, but occasionally high abnormal values were measured in some waters. It is therefore desirable to determine the dark fixation simultaneously along with the photosynthesis. Since the 14C-method is not fit for measuring respiration, proper allowances for respiration should be made in order to calculate the gross photosynthesis.
Influence of nitrate ions upon the growth of Chrysanthemum coronarium var. spatiosum was investigated by means of water culture, with special reference to dry matter production. 1) Absorption rate of nitrate ion and the juvenile growth of plants were almost independent of nitrate concentration of the medium. However, the maximal growth of plants was limited by the total amount of nitrogen available. 2) Nitrogen deficiency caused chlorosis, or chlorophyll content depression, in leaves, and accumulation of phosphorus in tissues, while it had no special effect on the content of ashes, calcium and iron. 3) Decrease of nitrogen concentration in tissues was persued at successive stages of growth. Critical nitrogen concentration in each organ, at which the growth should cease, was detected. 4) Marked recession of photosynthetic activity, and reduction of respiration in leaves and roots, but the increase of it in stems were observed being accompanied with nitrogen deficiency. Decrease of plant growth was also explained in the light of dry matter production.
When the isolated internodal cell of Nitella fexilis was cultured under pH gradient or IAA concentration gradient, which was given in culture medium, a new shoot and rhizoids were formed from the end which was placed in more adequate medium, whether this end was apical or basal. Sandan (1955) found that the morphogenetic polarity of the cell can be reversed by changing light condition. In the light of these experiments we are now in a position to say that the morphogenetic polarity in the cell of Nitella is certainly weak and is easily controlled by artificial treatment.