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.