1. 1. The unfolding of ribosomes from Escherichia coli renders ribosomal RNA (rRNA) susceptible to both specific and nonspecific nuclease action. 2. 2. The nuclease digestion produces a precipitate which contains most of the total ribosomal protein and 15% of the total RNA. 3. 3. RNA fragments isolated from the precipitate are heterodisperse, as judged by gel electrophoresis, and have a 28 (±7) nucleotide-residue chain length. 4. 4. The RNA fragments, obtained with nonspecific nucleases have a higher G and C content than intact rRNA. 5. 5. The concept, that the RNA fragments derive from nonhelical RNA regions, which in situ preferentially bind ribosomal proteins, is discussed. © 1969.