A Note on Cone-in-Cone Structure

The structure called cone-in-cone attracted my attention when I was working at certain forms of jointing and spherulitic structures in rocks, and has been studied in a desultoiy fashion ever since. Moreover, the Museum of University College possesses some good specimens of cone in-cone obtained by the late Prof. Morris, and I received a present of others, which had been used by Mr. W. S. Gresley for his suggestive paper when he left England for America. But though I formed some general conclusions on the subject, I abstained from writing, because I felt doubt concerning one point of importance, and had never seen a good example of cone-in-cone in the field.