H.G. Wells on Immunity and Natural Selection - The Birthr...

These germs of disease have taken toll of humanity since the beginning of things--taken toll of our prehuman ancestors since life began here. But by virtue of this natural selection of our kind we have developed resisting power; to no germs do we succumb without a struggle, and to many--those that cause putrefaction in dead matter, for instance--our living frames are altogether immune. But there are no bacteria in Mars, and directly these invaders arrived, directly they drank and fed, our mic...

 By the Toll of a Billion Deaths Have Humans Earned our Ri...

These germs of disease have taken toll of humanity since the beginning of things–taken toll of our prehuman ancestors since life began here. But by virtue of this natural selection of our kind we have developed resisting power; to no germs do we succumb without a struggle, and to many–those that cause putrefaction in dead matter, for instance–our living frames are altogether immune… By the toll of a billion deaths man has bought his birthright of the earth, and it is his against all comers; i...