From the published list of the papers read to the late Actuarial Society, it would appear that, notwithstanding its interest and importance, little or no attention was paid to the subject of reversions and other allied securities. This is probably accounted for by the fact that numerous able papers have been read from time to time to the Institute of Actuaries, and the field may have been considered as pretty well exhausted. The Institute papers, however, for the most part confine themselves to particular branches of the subject, many of them almost entirely to questions of formula ; and to a person beginning the subject, the variety and detail of such papers must be perplexing, not to say alarming. Especially will this be the case if the student is seeking information as to the actual business handling of reversionary transactions, for the theoretical is more frequently in evidence than the practical. It seemed, therefore, that it might not be useless to have a paper of the nature of an introduction to the practical working of reversions—a paper which might form a base for attacking the subject in its more complex developments—and the following notes have been written on these lines. I do not know whether anything of the nature of an apology is owing in respect of a paper which naturally embodies much that will appear commonplace to those familiar with the subject; but I take it that the aim of the Faculty is not only to stimulate original research, but also to encourage any work which is likely to be useful to junior members.