Population explosion.

Correspondence It would appear that four bodies are concerned , the driver, the public, the insurance companies, and the doctors. The first three might be taken together, for I understand that the insurance companies are no more concerned with the elderly driver as an insurance risk than with anyone else; in fact if the amount of premium required is a criterion he is considered to be less of a risk than the young driver. Again I would ask who has put up the quarry ? As far as the doctors are agreed (and it is about the only matter on which they are agreed) the blind should not be permitted to drive; the State debars epileptics, but here the doctors are at variance. Who is to be considered unfit to drive: the patient with too high or too low a blood pressure, the hyperglycaemic or the hypo-glycaemic, the psychopath, the ill-tempered, the inattentive, or the adventurous ? There is little difficulty in understanding why the doctors have not come to any conclusion. I would suggest that unfitness to drive lies not so much in senility or physical deformity as in the realm of Freud January, p. 75) conclude that " atrial systole has a powerful augmentative effect on stroke output in the normal heart, while its effect is less valuable when the myocardium is diseased." This is of great interest in relation to the clinical examination of the heart in health and disease. In health the effects of the left atrial contraction are neither audible nor palpable. In such diseases as hypertension, chronic ischaemic heart disease, aortic stenosis, muscular obstruction to the outflow from the left ventricle, and acute cardiac infarction the force of the left atrial contraction amounts to an "explosion." The shock-wave commonly is visible and palpable, and the noise is recognized as the " pre-systolic," "atrial," or " fourth sound" gallop. These clinical findings suggest that the atrial contraction is more powerful when the myocardium is diseased, and I should be most grateful if Dr. Gillespie and his colleagues would explain the paradox.-I am, etc., Obstetrics in Africa SIR,-I would like to thank Mr. Graham Cole for a thoughtful contribution (28 January, p. 238) on the subject of obstetrics in Africa. I must, however, disagree with his assessment of the operation of symphysio-tomy. He states that in Africa he met mothers "fleeing the nearby hospitals where this …