I should like to say first that I am extremely sensible of and greatly appreciate the honour that the Institute has done me by inviting me to submit this paper. In writing it I have felt throughout the difficulty that arises from the very different approach which a lawyer makes to legal decisions from that which an actuary may be expected to make. Cases interest me because of the niceties of construction they involve or of their subtle distinctions from other cases, or again because they mark the gradual development of the judicial mind in conformity with the public opinion of the preceding generation. To actuaries the interest of cases must primarily lie in their bearing on the practical problems of life assurance work. In discussing cases, therefore, I have felt that the reaction of readers will be sometimes that I have been labouring a decision that was obvious from the start, at others that the point at issue is obsolete because no company has had such a condition in its policies for the last ten years or for some equally good reason. Knowing next to nothing of life assurance practice, I have been unable to avoid this defect, and can only ask that it be excused.