62 



THE PHYSIOLOGY OF REPRODUCTION 



about half the month, when it rises to half a degree above the mean. 

 It falls below the mean line just before the onset of menstruation, 

 during which it remains about half a degree below. Similar results 

 were obtained by Reiul, Ott, and Giles, 1 but Vicarelli 2 and certain 

 other authors have recorded an increased temperature during 

 menstruation. 3 Zuntz, 4 however, as a result of more recent experi- 

 ments, says that there is a regular lowering of the temperature 

 throughout the menstrual period, after which it rises to the normal. 

 Stevenson states also that the curve of urea excretion follows 



25 



FIG. 1. Diagram illustrating the " Wellenbewegung " hypothesis. The 

 curve AB represents the varying intensity of the vital processes 

 during the twenty-eight days of the menstrual cycle. The numbers 

 between m and n represent the days occupied by menstruation. 

 (From Sellheim.) 



a similar course to the temperature curve, and that, speaking 

 generally, there is an increase in metabolism coincident with the 

 time of development of the uterine mucosa. There is, however, no 

 doubt much truth in von Noorden's criticism 5 that the " menstrual 

 wave " hypothesis has given occasion to many premature conclusions 



1 Giles, "The Cyclical or Wave Theory, etc.," Trans. Obstet. Soc., London, 

 vol. xxxix., 1897. 



2 Vicarelli, " La temperature de Puterus dans ses diverses conditions 

 physiologiques," Arch. Ital. de Biol., vol. xxxii., 1899. 



3 Sfameni, " Influence de la menstruation sur la quantite d'h&uoglobine," 

 Arch. Ital. de Biol., vol. xxxii., 1899. 



4 Zuntz (L.), "Einfluss der Ovarien auf den Stoffwechsel," Arch. f. Gyntik., 

 vol. Ixxviii., 1906. 



5 Von Noorden, Metabolism and Practical Medicine (English Translation), 

 vol. i., London, 1907. 



