The metabolism of RNA and protein in the gametophytes of bracken fern (Pteridium aquilinum) is affected by the quality of light in which they are grown. When sporelings were grown as two-dimensional gametophytes in blue light, particulate fractions separated from the sporelings exhibited greater incorporation of uridine-(3)H and leucine-(3)H into RNA and protein, respectively, than those from sporelings grown as one-dimensional protonema in red light. After various periods of exposure of gametophytes to red or blue light in the presence of uridine-(3)H, the nuclei-rich fraction showed the highest specific activity in RNA, and irrespective of incubation time, blue light was more effective than red light. The possibility that enhanced synthesis of RNA in the nucleus in response to blue light is significantly related to the morphological growth pattern of the gametophytes, is discussed.
Proof that a patient is suffering from sulfone-resistant leprosy depends on demonstrating that his bacilli can multiply in the mouse foot pad even when the mice are fed sulfone in the diet. Hitherto the maximal dose of DDS tolerated by the mouse has been used in such tests. This paper concerns a patient whose bacilli multiplied in mice fed lower doses of DDS, but were inhibited when the maximal dose was used . His clinical features are distinctive and probably characteristic of this type of "partial" resistance. It is likely that more cases of this type will be found . Recommendations are made concerning the investigation of possible DDS-resistant leprosy patients and their treatment.