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Demography 367
hasten to indicate the consequences which any big increase in the proportion
of male births, as compared with the present proportion of 51 boys to 49 girls,
could have on the development of populations in the various countries. There
is also the possibility that the percentage of males could be at the mercy of
changes in fashion.
In the past, certain populations, by resorting to infanticide, have already
carried out such a choice of sex, and the difficulties they have encountered offer
an indication of what a choice at the time of conception could entail. Certain
tribes of Eskimos which saw in the male infant a potential hunter and in the
female infant a useless mouth to feed, have resorted to the systematic killing of
girls at birth. Obviously, this brought about an imbalance between the sexes
which no longer enabled the population to reproduce itself.
The mastery of old age
48. In a still longer term development, one can look forward to the discovery by
biology of the mechanisms of the ageing of the organs. The ageing of each
individual begins at the precise moment when the ovule is fertilized by the sper-
matozoa. It presents itself as a kind of successive forgetfulness of the biochemi-
cal cycles built up on the basis of the information contained in the genetic
heritage. The child who has just been born can already no longer produce cer-
tain substances which he manufactured perfectly well in his mother’s womb.
Thus the life of an individual can be viewed as the perpetual creation of new
machinery for replacing older machinery which no longer works and which he
no longer knows how to build. Death happens when the inventive faculty itself
ceases.
Such are the apparent facts. But what is the profound reason for this non-
remembrance which forces the individual to keep on inventing in order to
survive? We do not know. Biology has set about trying to solve the problem and
we may expect that a solution to it wil emerge progressively in the course of the
next century.
From the demographic point of view, the chief result wil be the progressive
disappearance of old-age diseases and, consequently, the postponement of
endogenous mortality. This will have little effect on population growth, but
considerable effect on its age composition. Whereas hitherto the lowering of
the death-rate has scarcely had any effect on the age composition, the disap-
pearance of endogenous forms of death will result in a noticeable increase in
the percentage of old people, with economic and social consequences of which
there is no need to remind the reader.
Infertility overcome
49. Suppose we go even further? We are then in science fiction. There is a
phenomenon which is connected with the ageing process: the progressive devel-
opment of female infertility between puberty and the menopause. A better
knowledge of the causes of old age wil no doubt enable us to understand better
how it is that woman loses her reproductive powers, and then perhaps to prevent
her from losing them. However, we must face the fact that here we are dealing