“…concentration. Why our findings differ from Basu's (1970) is difficult to explain. His patients may have differed in some relevant way from our subjects, since women who seek medical help may do so primarily because of a recent change in the volume of blood lost at menstruation, and such a change might be associated with temporarily increased local intrauterine fibrinolysis and so be reflected in raised systemic levels of serum F.D.P.…”