The results concerning the nature of ARN present in the spore dependent on the method of extraction, several methods were compared. 35 of the sporal RNA, as judged by physical characteristics 4 S and function, is transfer RNA the corresponding figure for bacteria is 17. Ribosomal RNA 16 S and 23 S constitutes 65 of the sporal RNA. While in the vegetative form all of the ribosomal RNA is present in ribosomes, in the spore only about 5 of the ribosomal RNA exists in this form, the remaining being present in a non- particulate form, highly sensitive to degradation. The presence of an RNA of messenger type has not been revealed by sedimentation analysis or by hydridation tests.