THE SYMPATHETIC SYSTEM 239 



according to Ancel and Bouin, is due to a hormone in the 

 mother's milk originating from the placenta. 



At puberty the increase in the size of the breasts appears 

 at the same time as the other secondary sexual character- 

 istics. This growth is controlled by the corpus luteum. 



In the same way, the congestion of the breasts preceding 

 menstruation, are due to the corpus luteum. The 

 prickling sensations and the tension of the breasts dis- 

 appears after menstruation; that is, at the time when the 

 corpus luteum degenerates. 



The increase in the size of the breasts during the first 

 few months of pregnancy is also due to a hormone coming 

 from the corpus luteum, which lasts much longer than 

 that of a corpus luteum of menstruation. This is a 

 physiological hypertrophy, which regresses after delivery. 



Such are the physiological reactions of the mammary 

 gland to the action of the genital system. 



Next to these physiological facts, are certain patho- 

 logical observations, the mechanism of which is still 

 unknown and which we will successively study in woman 

 and in man. 



I. MAMMARY HYPERTROPHY AT PUBERTY IN WOMEN. 



This is a peculiar affection found in girls between 11 

 and 16. 



The breasts increase in size; they become firm and 

 prominent. Their consistency is uniformly hard and 

 resembles that of the normal breast. The skin is 

 freely movable. 



Very quickly the breasts, whose volume increases, be- 

 come pendulous. The skin becomes distended and the 

 veins dilate. The nipple flattens out or becomes invagi- 

 nated. In a few months these breasts become two 



