1146 THE REPRODUCTIVE ORGANS 



substantiation in the experiments of Kruiger and Offergeld, 1 which 

 prove that even the denervated uterus may show a normal onset of 

 labor. In addition, Sauerbruck and Heide 2 have demonstrated that 

 artificially united female rats (symbiosis) may influence one another. 

 Thus, it was noted that the onset of the uterine contractions in one 

 invariably produced these contractions in the other animal. If, 

 however, the other was not pregnant, it then showed certain symptoms 

 indicative of a serious illness. Eden 3 and Williams 4 have called atten- 

 tion to the fact that the placenta undergoes senile changes at term 

 which increasingly interfere with the nutrition of the fetus. The 

 accumulation of the waste products resulting in consequence of this 

 condition, undoubtedly evokes local stimuli which diminish the output 

 of nitrogen, and depress the general processes of oxidation. Conse- 

 quently, we are forced to conclude that labour is under the direct control 

 of a local mechanism which may be activated either chemically or me- 

 chanically. The central nervous system, on the other hand, serves 

 merely as a regulating and correlating agent. It is a well-known fact 

 that emotions and other sensory impressions may influence the onset 

 and progress of labor as decidedly as the activated uterus may alter 

 the functional state of other organs. 



1 Archiv fiir Gynec., Ixxxiii, 1907, 257. 



2 Miinchener med., Wochenschr., 1910. 



3 Jour, of Path, and Bact., 1897. 



4 Jour, of Obst., xli, 1910. 



