HORMONES AND THE MAMM^ 91 



nancy before the mammae undergo much change ; and 

 oophorectomy during pregnancy does not interfere with 

 subsequent lactation 1 . 



Again, Ott and Scott 2 state that extract of corpus 

 luteum increases the flow of milk ; but, on the other 

 hand, Frank and linger 3 have shown that no stimulation 

 of the mammae can be obtained by the injection of the 

 extract, even when homogenous, in non-lactating animals. 



Further, in women at a menstrual period the breasts Mammary 

 may show signs of activity, and this has been held to aui 

 prove that the internal secretion of the corpus luteum is struation 

 responsible for the change. The investigations of Bouin 

 and Ancel 4 , and also those of O'Donoghue 5 , apparently 

 support this view, but it seems to me doubtful whether 

 it represents the whole cause and effect. I shall discuss 

 mastidynia later, but it may be mentioned here that mens- 

 trual swelling and tenderness in the breasts is probably 

 due to an attempt on the part of regulators of metabolism 

 to excrete lime salts by way of the mammary glands 

 at this period ; or, alternatively, that a high calcium 

 content in the blood, such as is found before menstrua- 

 tion, leads to activity in the mammae. This is entirely 

 confirmed by the fact that with the onset of menstrua- 

 tion the pain and swelling in the breasts immediately 

 disappear, for this would not happen if the corpus 

 luteum were the cause of the disturbance. Further, 

 the ripening of the corpus luteum does not necessarily 

 coincide with menstruation. This last objection, how- 

 ever, is open to the argument that all women do not 

 suffer with tenderness in the breasts during menstrua- 

 tion ; nevertheless, a majority probably do. 



It may be said, then, that the ovary influences the 



1 Marshall, F. H, A., and W. A. JoUy, Proc. Roy. Soc., Ser. B, 

 1905, vol. cxcviii, p. 99. 



2 Ott, I., and J. C. Scott, Proc. Soc. Exper. Biol and Med., 1910-11, 

 vol. viii, p. 48. 



3 Frank, R. T., and A. Unger, Archiv. Inter. Med., 1911, vol. vii, p. 812. 



4 Bouin, P., and P. Ancel, Compt. Rend. Soc. Biol., 1912, vol. Ixxii 

 p. 129. 



5 O'Donoghue, C. H., Quart. Journ. Micr. Soc., 1911, vol. Ivii, p. 187. 



