All these artificial preparations for intercourse demand from the woman an investigation of and interference with her own internal organs, which is revolting to all decent women, and such teaching is directly opposed to the advocacy of cleanliness and non-interference with the genital organs, which is the natural habit of healthy-minded women. The effects, however, go further than this. Nature has provided in the healthy vaginal secretions an antidote to infection which quickly destroys harmful germs. If the natural secretions are altered it is difficult to restore them to their natural quality. Professor Arthur Thomson, F.R.C.S., has shewn ("British Medical Journal," January 7th, 1922) from observations of the lining of the womb in animals and in women that "the weight of evidence goes to prove that its function is more likely to be absorbent than excretive, and that as such it plays an important part in the animal economy." 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.