The most important practical question arising in an actuary's practice is the following—“By what table of mortality, and according to what process, should the liabilities of a Life Assurance Company be estimated ?” Very wide differences of opinion appear to exist as to the proper answer to be given to this question. Thus, in the Assurance Magazine for January last, are contained two papers, written respectively by Mr. Jellicoe and Mr. Tucker, which bear more or less upon this subject ; and in which very conflicting opinions are expressed by those experienced actuaries.