THE suggestion first made in NATURE (131, 117; 1933) by Dr. L. J. Spencer that tektites have been formed by the fusion of terrestrial rocks by the fall of very large meteorites has given rise to an interesting discussion, but, being unexpectedly novel, it has not met with general acceptance. Prof. F. E. Suess of Vienna, in whose classical paper of 1900 the name tektite was introduced and the meteoritic theory first proposed, has returned to the subject and he gives a recent review in Die Naturwissenschaften (21, 857, Dec. 8, 1933). Here, and in a private letter, he admits that the Darwin glass of Tasmania may have been formed by the fusion of terrestrial material. Some of the silica-glass from the meteorite craters at Wabar in Arabia is, in fact, exactly like Darwin glass in every respect, and at both places the material is present in thousands of tons. But from Tasmania no meteoric iron or craters have been recorded. For other tektites (australites, billitonites, moldavites and ‘indochinites’), Prof. Suess still holds to the meteoritic theory. He points out that they have a much wider distribution than the silica-glass found around meteorite craters, and also that they usually bear no relation in chemical composition to the underlying rocks. The same arguments are also put forward in a letter to the Editor from Mr. T. Hodge-Smith, of the Australian Museum, Sydney, who has given an account of the tektites recently found in the Philippine Islands. These arguments, however, overlook the fact that tektites are usually found in alluvial deposits and that they are often water-worn and corroded, indicating that they have been transported from their place of origin. In the case of australites found scattered on the surface of the ground over wide areas, it is conceivable that they have been transported by the natives.