for the results of their observations in their own countries in regard to all classes of people. He at length published a symposium of the answers showing the prevalence of trachoma in different countries and among the different classes of people. As given in this contribution there seemed to be a confused accumulation of facts which had, on the whole, apparently little meaning. Peoples of contiguous countries, of the same color and not very different in habits of life, were reported as differing widely in respect to the prevalence of the affection. No reasons were assigned and none seemed to be suggested by the varying facts. An analysis which I made of this report showed that among peoples with the 'medium' or tall heads, like the Irish and the Italians, trachoma is rife; while among peoples with the broad head, like the Bavarians, or with the long head, like the negroes whose ancestors were from the West or Guinea coast of Africa, trachoma did not prevail; but it is interesting to note that descendants of the negroes of the northern part of Africa, where the heads of the natives are often tall, are subject to trachoma equally with the whites among whom they live. I have in another connection discussed this question at more length.[1]
Turning to a larger and more important subject, the negro is known to be especially subject to tubercular diseases, yet he is, to an unusual degree, immune from consumption. In my investigations during the past few years, I have not seen a consumptive the direction of whose visual plane was not much higher than the standard. We shall come to this from another point of view. It is easy to see that
- ↑ 'Transactions of the British Medical Association,' 1897.