Page:Popular Science Monthly Volume 77.djvu/27

Rh lion and tiger, have in most places been destroyed; but the small insidious germs or bacteria remain with us. Through a process of natural selection, we have acquired a comparative tolerance of or immunity from several of them, but they have at all times heavily taxed our resources, and have actually been the means of exterminating many races. It is perhaps not unlikely that man would have died out before this, had he been confined to any limited region; but since his distribution has always been wider than the prevalence of any one disease, he has managed to survive in spite of all of them.

A very interesting discussion of the insidious parasites of disease has been given by Dr. Ronald Ross in an address on "Malaria in Greece," delivered before the Oxford Medical Society. This is quoted, with much other pertinent matter, by Dr. L. O. Howard in Bulletin 78, Bureau of Entomology, U. S. Department of Agriculture (1909).

We now come face to face with that profoundly interesting subject, the political, economical and historical significance of this great disease. We know that malaria must have existed in Greece ever since the time of Hippocrates, about 400 B.C. What effect has it had on the life of the country? In prehistoric times Greece was certainly peopled by successive waves of Aryan invaders from the north—probably a fair-haired people—who made it what it became, who conquered Persia and Egypt, and who created the sciences, arts and philosophies which we are only developing further to-day. That race reached its climax of development during the time of Pericles. Those great and beautiful valleys were thickly peopled by a civilization which in some ways has not been excelled. Everywhere there were cities, temples, oracles, arts, philosophies and a population vigorous and well trained in arms. Lake Kopais, now almost deserted, was surrounded by towns whose massive works remain to this day. Suddenly, however, a blight fell over all. Was it due to internecine conflict or to foreign conquest? Scarcely; for history shows that war burns and ravages, but does not annihilate. Thebes was thrice destroyed, but thrice rebuilt. Or was it due to some cause, entering furtively and gradually sapping away the energies of the race by attacking the rural population, by slaying the new-born infant, by seizing the rising generation, and especially by killing out the fair-haired descendant of the original settlers, leaving behind chiefly the more immunized and darker children of their captives, won by the sword from Asia and Africa?. . . The whole life of Greece must suffer from this weight, which crushes its rural energies'. Where the children suffer so much how can the country create that fresh blood which keeps a nation young? But for a hamlet here and there, those famous valleys are deserted. I saw from a spur of Helicon the sun setting upon Parnassus, Apollo sinking, as he was wont to do, toward his own fane at Delphi, and pouring a flood of light over the great Kopaik Plain. But it seemed that he was the only inhabitant of it. There was nothing there. "Who," said a rich Greek to me, "would think of going to live in such a place as that?" I doubt much whether it is the Turk who has done all this. I think it is very largely the malaria.

Until recent times, the success of mankind in weathering the dangers of disease has been mainly due to the precautions he has been able to take, along with the limited distribution of diseases, and the process of evolution against them. In the future with the aid of science there can be little doubt that the bacteria of many will be