Nucleic acid is an ideal hereditary material both for stability of information storage and ease of duplication and repair. From the viewpoint of information theory2,3 biological organisms are exceedingly complex and perhaps only nucleic acid can store efficiently the required large quantities of information. This may be true for molecular coding but morphological differences as between species may be achieved by simple transformations of scale4 and little information may be required to direct early egg development.5 It is also difficult to sustain the argument that efficient storage is important when much DNA in higher organisms is non-coding.