Recently Dr. Paul Gaedeken of Copenhagen has argued in a detailed statistical study ("La Réaction de l'Organisme sous l'Influence Physico-Chimiques des Agents Météorologiques," _Archives d'Anthropologie Criminelle_, Feb., 1909) that the conception-rate, as well as the periodicity of suicide and allied phenomena, is due to the action of the chemical rays on the unpigmented skin in early spring, this action being physiologically similar to that of alcohol. He seeks thus to account for the marked and early occurrence of such periodic phenomena in Greenland and other northern countries where there is much chemical action (owing to the clear air) in early spring, but little heat. This explanation would not cover an autumnal climax, the existence of which Gaedeken denies. In order to obtain a fairly typical conception-curve for Europe, and to allow the variations of local habit and custom to some extent to annihilate each other, I have summated the figures given by Mayr for about a quarter of a million births in Germany, France, and Italy,[156] obtaining a curve (Chart 2) of the conception-rate which may be said roughly to be that of Europe generally. If we begin at September as the lowest point, we find an autumn rise culminating in the lesser maximum of Christmas, followed by a minor depression in January and February. Then comes the great spring rise, culminating in May, and followed after June by a rapid descent to the minimum. In Canada (see e.g., _Report of the Registrar General of the Province of Ontario_ for 1904), the maximum and minimum of conceptions alike fall later than in Europe; the months of maximum conception are June, July, and August; of minimum conception, January, February, and March. June is the favorite month for marriage. It would be of some interest to know the conception-curve for the well-to-do classes, who are largely free from the industrial and social influences which evidently, to a great extent, control the conception-rate. It seems probable that the seasonal influence would here be specially well shown. The only attempt I have made in this direction is to examine a well-filled birthday-book. The entries show a very high and equally maintained maximum of conceptions throughout April, May and June, followed by a marked minimum during the next three months, and an autumn rise very strongly marked, in November. There is no December rise. As will be seen, there is here a fairly exact resemblance to the yearly ecbolic curve of people of the same class. The inquiry needs, however, to be extended to a very much larger number of cases.