128 PLAIN FACTS FOE OLD AND YOTJNG 



3. If the ovule becomes impregnated, tlie menstrual 

 decidua is developed into the true decidua of preg- 

 nancy. 



4. If in a certain time, which represents its vitality, 

 the ovule is not impregnated, it dies, and thus causes 

 congestion and disintegration of the menstrual decidua ; 

 that is, the menstrual flow. 



5. The congestion reacts on the cause of its origin, 

 the ovaries, and brings about a rupture of a follicle, 

 which, in the meantime, has ripened. (This does not 

 exclude any other cause which might bring about 

 menstrual congestion, as a cause of a ruptured 

 follicle.) 



This view not only explains all contradiction, but 

 also solves many doubtful questions in a satisfactory 

 manner. 



The basis of this view is : 



1. That the unimpregnated ovule becomes im- 

 bedded. 



2. That after this imbedding, and only then, it has 

 a certain limited individual life power. 



Many objections might be urged against this theory. 

 Some authorities claim that impregnation always takes 

 place at the ovary, and that extra-uterine pregnancy 

 tends to prove this; but as extra-uterine pregnancy 

 occurs once in ten thousand cases, the chances are ten 

 thousand to one that impregnation does take place in 

 the uterus. 



The following conditions are necessary for the im- 

 bedding of the ovule at the next menstrual process: 



1. The ovule must be perfectly ripe. 



2. It must pass from the follicle at a time when it 

 has the best chance to soon reach the uterus through 

 the Fallopian tubes during menstruation. 



