Page:First course in biology (IA firstcourseinbio00bailrich).pdf/466



What rate of adjustment to new environment is possible for man? This has not been ascertained; it is probably much slower than has been generally imagined. The natives of Tasmania, New Zealand, and many of the Pacific Islands became extinct in less than a century after adopting clothing and copying other habits from Europeans. Life in the country in civilized lands differs less from the environment of primitive man than does life in cities. Cities have been likened to the lion's cave in the fable, to which many tracks led, but from which none led. The care of health in cities is now making rapid strides along the biological basis of purer air, more open space, less noise, simple food, and pure water. Biology, by supplying as a standard the conditions which molded man's body for ages, furnishes a simple and sure basis for hygiene. To mention one instance among many, man blundered for centuries in attempting the cure of consumption, and well