These circumstances then, as we have said, contribute to cause the difference between women and the other animals in this state, but the most important thing is this: in some animals the discharge is small, and in some not visible at all, but in women it is greater than in any other animal, so that when this discharge ceases owing to pregnancy they are troubled (for if they are not pregnant they are afflicted with ailments whenever the discharges do not occur); and they are more troubled as a rule at the beginning of pregnancy, for the embryo is able indeed to stop the discharges but is too small at first to consume any quantity of the secretion: later on it takes up some of it and so alleviates the mother.