The successive stages in the history of life assurance business are closely associated with certain developments of actuarial science, and in particular with the appearance of the great Life Tables, the Northampton, the Carlisle, the Seventeen Offices, and the Twenty Offices experience. More recently the British Offices experience of 1863-1893 has been published, and it can by no means be asserted that all the lessons to be derived from this important mass of statistics have been learnt. Many valuable opinions have been expressed on particular points, in Great Britain, in North America, and elsewhere, but as a rule any proposals as to rates of premium would appear to have left some appreciable margin for adverse contingencies as regards allowance for mortality, for interest, and for expenses. Yet in the practical conduct of business under competitive conditions, the problem that ever presses for solution touches closely the present actual cost price, and although this may be but a will-o'-the-wisp, and undoubtedly varies greatly in different circumstances, it is probable that experienced actuaries will always find features worthy of discussion in connection with it.