562 THE PHYSIOLOGY OF REPRODUCTION 



Franz, 1 and others have confirmed Kehrer's observation, thus 

 proving that the movements are not dependent on impulses received 

 from the central nervous system. Those investigators showed that 

 the excised uterus may undergo regular contractions for a prolonged 

 period if placed in a warm bath of normal saline solution or on 

 having . its vessels perfused with Locke's solution. According to 

 Franz the excised virgin uterus exhibits no spontaneous contractions, 

 but Helme and Kurdinowski state that they may occur, but that they 

 are much weaker than those taking place during and after pregnancy. 

 The movements of the uterus have lately been mor,e fully 

 investigated by Cushny, 2 who has carried out a large number of 

 experiments upon rabbits and other animals. This author states 

 that in virgins the unexcised uterus may remain motionless for a 

 long time, but that after manipulation or exposure to air rhythmic 

 contractions are often developed. He is disposed to believe, there- 

 fore, that the virgin uterus in the intact animal undergoes no 

 spontaneous movements. In animals in a state of "heat," and 

 during and after pregnancy, spontaneous contractions could generally 

 be discerned from the first, and the author is doubtful if the organ 

 ever resumes its original inert condition after it has once been 

 pregnant. In some cases the movements seemed to occur almost 

 simultaneously throughout the entire organ, but in others the 

 circular muscle fibres contracted independently of the longitudinal,' 

 and vice versa. Mechanical or electrical stimulation caused very 

 powerful contractions, but these were elicited more easily in the 

 pregnant than in the virgin uterus, while the increased irritability 

 was found to persist after pregnancy was over. 



Helme stated that a shutting off of the blood-supply in the 

 excised and perfused uterus of the sheep brought about contraction. 

 Kurdinowski, on the other hand, found that in the intact animal the 

 opposite effect was produced. Cushny's experiments for the most 

 part confirm those of Kurdinowski, but clamping the aorta in the cat 

 led to conflicting results, since in two cases it was succeeded by 

 relaxation and in three by contraction. No reason could be assigned 

 for this divergence. 



It has long been known that uterine contractions can be indiiced 

 by nervous stimulation. 3 Thus Serres 4 showed that irritation of the 



1 Franz, " Studien zur Physiologic des Uterus," Zeitsck. f. Gebvrt. u. Gyndk., 

 vol. liii., 1904. 



2 Cushny, " On the Movements of the Uterus," Jour, of PhysioL, vol. xxxv., 

 1906. 



3 Feldman(7%e Principles of Ante-Natal and Post-Natal Child Physioloyy, 

 London, 1920) states that there are probably centres for uterine contraction 

 in the cortex, medulla, and cerebellum, since stimulation of these areas causes 

 uterine contractions, but he does not cite his authorities. 



4 Serres, Anatomif Compare'c dn (''-wax, 1824. 



