Abstract
When the skin of mice of strain A was irradiated in vitro with ultraviolet light the phospholipid fraction diminished and the phosphorus that disappeared from this fraction appeared as acid-soluble phosphorus or as "ribonucleic acid phosphorus". The fractions of phospholipid affected were ethanolamine plasmalogen (72% destruction) and, to less extent, phosphatidylethanolamine (21% destruction). No significant changes were seen in deoxy-ribonucleic acid or ribonucleic acid with the methods used.