After describing at length the evidence that the male secretion consists largely of the secretions from special glands as well as the sex cells, he refers to the fact that these are all largely received into and absorbed by the glands of the womb, and he discusses the probability that such absorption profoundly and beneficially affects the physiological reaction in the woman.  He points out that the use of artificial checks “while preventing fertilisation may also be the means of depriving the female of certain secretions which may exercise a far reaching influence on her economy”; and he concludes, “As a rule we cannot interfere with the normal course of nature without some consequent evil result.  May this not be an instance in which for some apparent gain in one direction, the woman pays the penalty?”

CHAPTER IV

THE EFFECT OF WIDESPREAD CONCEPTION CONTROL ON NATIONAL EFFICIENCY

In every nation individual capacity varies within wide limits.  We have men and women of brilliant attainments, and of all grades of intelligence ranging downwards to the mentally defective.  There is no doubt that all grades of intelligence can be improved by education, but there appears to be a limit to the capacity of development of each individual.  Lower intelligence, therefore, is not only due to lack of opportunity, but to an inborn constitutional defect.

Further study has shewn this defect to be hereditary—­the parents or grandparents of such people shew defective intelligence, and their offspring are likely to do the same; indeed, if two mentally defective people marry it is fairly certain that their children will all be mentally defective.

There are, however, no sharply defined classes of intelligence; just as the mentally defective are in many grades, so ordinary men and women vary from low or average intelligence up to outstanding cases of genius or capacity.

By the newer methods of mental testing it has been shewn that children of various classes of the community, as well as men and women of different races, can be grouped according to their intellectual capacity, and that no educational facilities will develop that capacity beyond a certain point.

Professor W. McDougall, F.R.S., in his most useful and interesting book on National Welfare and National Decay, reaches the important conclusion “that innate capacity for intellectual growth is the predominant factor in determining the distribution of intelligence in adults, and that the amount and kind of education is a factor of subordinate importance.”  He claims that the evidence is overwhelming as to the validity of the results obtained by mental testing.

A few examples of experimental work given in Professor McDougall’s book will suffice to show the trend of these results.

Tests of intelligence were carried out on recruits for the American Army, white and coloured, and they shewed marked superiority of the white race.