^{page 97 note 1} Of human scientists, those creatures of knowledge, power and potentiality for good or ill, 90 per cent of all those who have ever existed are calculated to be alive to-day.

^{page 97 note 2} A convenient general summary is provided in World Population and Resources. Political and Economic Planning, London, 1955. This work satisfactorily covers not only food and other biological resources but mineral and energy resources in addition.

^{page 98 note 1} These matters are conveniently set out by the present author in a chapter “What are People For?” in the symposium volume The Humanist Frame, edit. Sir Julian Huxley, 1961.

^{page 98 note 2} Antarctica, the last continent to be colonized, now regularly has a few overwintering males, and male summer migrants are numerous. Female visitors are still very scarce. Conception is known to have occurred, but as yet no birth has been recorded in Antarctica.

^{page 98 note 3} The exact proportion (whether one-third, one-half or two-thirds) is debatable and lacking in definition, and is irrelevant to the present discussion.

^{page 99 note 1} The faunistic dangers of chemical control are at last becoming more widely recognized.

^{page 100 note 1} Crowding may now be such that even the enthusiasm of the cognoscenti must be checked: the Royal Society for the Protection of Birds has had some recent distressing examples.

^{page 101 note 1} The International Planned Parenthood Federation is the co-ordinating central pressure group. As yet Japan is the only country in which the change from high fertility to low (from thirty-four to seventeen per thousand of population per year) has been brought about in a short time by deliberate intention. India is one of the countries now in which really strenuous efforts are being made, under governmental leadership, to bring population growth under rational control. Some others strive but success is slow to come. Indubitably a sensible momentum is developing in these matters in many parts of the world, but fundamentally what matters is that the rate of change of attitude and practice shall match the everincreasing need.