"The conditions under which the individuals live here are in both cases practically the same. The difference, therefore, does not appear to arise from any factor acting immediately and directly on the individuals, but to be connected with something' more remote. To me there seems but one solution of the matter; the peculiarity depends upon inherited differences, in fact, on racial characteristics."—Dr. Grieve, British Guiana Medical Annual, March 1, 1890.
I have not been able to gather anything very definite concerning the Chinese in their relation to tuberculosis; but considering how many and large are their cities, how ancient their civilization, how filthy their habits, and how crowded their dwellings, especially the sleeping apartments, they should be of all the races of the world the most resistant, if not against .tuberculosis, which infests in particular houses of the European type, yet against many other non-malarial zymotic diseases.
Measles.—Since measles, though very prevalent, is not very fatal, at least not so fatal as either malaria or tuberculosis, evolution against it is not nearly so marked as against either of those diseases. Its microbes secure their specific persistence by a rapid passage from host to host, and by an enormously rapid rate of multiplication. Nevertheless, all observers are agreed in declaring that it is more fatal when afflicting races to which it is strange than it is when afflicting races to which it is familiar—i. e. it is sufficiently death-dealing to have caused some evolution against itself. But all observers are also in agreement in thinking that the greater malignancy of type it displays when attacking the natives of the New World is to be attributed to improper medical treatment of the sick, or to lack of treatment rather than lack of resisting power. From
