SUMMARY In a population which does not practise birthcontrol the distribution of interval durations between marriage and first rank birth is of peculiar interest, as it depends on two basic factors in fertility : fecundity and foetal mortality. Due to their source, the data are not devoid of...

Henry Louis. ? Comments about Observation in Demography. As in many other fields observation and population statistics have been developed through the cumulative effect of historical events and therefore are not fully adequate. In new countries, for instance, the statistical material is gathered...