Abstract
Synchronous replication of chromosome and hybridization between ribosomal RNA (16S and 23S RNA) and DNA in Bacillus subtilis has shown that (1) 16S and 23S ribosomal RNA''s hybridize with DNA independently from each other, suggesting that there are loci or locus different for each of them, (2) to the genetic loci for 16S and 23S RNA are not scattered over the chromosome but confined to a restricted region between the adenine and threonine markers, and (3) the loci for 16S and 23S RNA should be close together.