AT the end of last year, Prof. C. G. Cullis retired from the chair of mining geology which he had held at the Imperial College of Science and Technology, London, since 1930. He became a student demonstrator in the Geological Department of the College so long ago as 1890, and was thus a member of the staff for nearly half a century, having been professor of mineralogy before he was appointed to the chair of mining geology. Prof. Cullis's former colleagues and students, many of whom are scattered over all parts of the world, recently assembled at the College to present an album to him containing their signatures, and to record their appreciation of his work and influence. In this tribute the subscribers say: "Generations of students will ever remember Professor Cullis as the ideal university lecturer. To few is given the skill to expound with such grace and effect the great truths of geology. We know the labour that is necessary for the attainment of apparent ease and simplicity: and here we see an apt example of ars est celare artem. But not only as a teacher will his students remember him: as a wise friend and mentor he was always accessible, and expert alike in directing their studies and in helping them to find their feet in the great world outside the College." In addition to the album, a cheque for the balance of the fund subscribed was presented to Prof. Cullis and a handsome electric clock to Mrs. Cullis and him jointly. Prof. Cullis has presented the cheque to the Governing Body of the College, with the suggestion that the income accruing from it should be used for the benefit of the mining geology department or students at the discretion of the professors of geology and mining geology department with the rector. The Governors have accepted this gift, and have resolved that the name of Prof. Cullis should be associated with the fund.