Title: THE MOLECULAR WEIGHT OF RIBOSOMAL RIBONUCLEIC ACIDS AMONG THE PROTOSTOMIA
Abstract: The molecular weights of the two larger rRNAs (18S and 26S) of one deuterostome and five protostomes were determined from their electrophoretic mobility. The molecular weight of the smaller (18S) ribosomal RNA was the same in all groups tested, but the molecular weight of the larger ribosomal RNA (26S) was 14 per cent smaller among the protostomes than the corresponding RNA (28S) of the deuterostomes.