In the absence of these definite indications, it is necessary to be cautious in coming to a diagnosis. Failing such caution, mistakes which may entail serious consequences are likely to arise. Two cases are known to me in which, after suspicion had rightly or wrongly been aroused, the child's most harmless movements were regarded as masturbatory in character. If a child becomes aware that its mother or some other person in authority is making such a mistake, the effect will naturally be very unfavourable. We have also to reckon with the fact that children who are somewhat older, from eight or nine years upwards, hardly ever masturbate when others are present, but only when they believe themselves to be unobserved--in bed, in the closet, or when out walking. In such cases it is hardly possible to diagnose masturbation with certainty; more especially in view of the fact that the signs that may betray an older boy--stains on the shirt or other articles of underclothing--are usually lacking during the first two periods of childhood. It must be added that such stains on linen resulting from ejaculation do not at first contain spermatozoa, and for this reason their diagnostic value is greatly lessened (see pp. 52-56). Still, the possible appearance of these stains is a matter to which attention should always be paid, and this in girls as well as in boys. In many instances, also, our diagnosis may be supported by the discovery of articles used for onanistic[80] purposes. In the case of boys we shall seldom, comparatively speaking, be able to do this; although, even in boys, operation is sometimes needed for the removal of articles used for onanistic purposes, which have found their way into the urethra or the bladder. In girls, such operations are more frequently required. Hairpins, pencils, and various other articles used for onanistic purposes, are from time to time removed from the vagina or the female bladder. Other signs that are supposed to indicate the habitual practice of masturbation are of little diagnostic value. It is traditionally held that masturbation in girls leads to elongation of the clitoris, but there appears to be no warrant in fact for this opinion. As I have previously pointed out, laceration of the hymen does not in general result from masturbation. Other signs, such as local irritation or swelling, are hardly ever seen in boys, and in girls are seen only in cases in which they masturbate to excess. _In girls, moderate reddening of the external genital organs has no significance whatever; and I take this opportunity of giving a special warning against inferring from the existence of such reddening that masturbation is practised, and also against attaching any importance to this symptom in a case in which a sexual assault is supposed to have been committed on a little girl._