528 THE PHYSIOLOGY OF REPRODUCTION 



undergoes no spontaneous movements. In animals in a state 

 of " heat," and during and after pregnancy, spontaneous con- 

 tractions 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 fibre con- 

 tracted 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 ofE of the blood-supply in the 

 excised and perfused uterus of the sheep brought about con- 

 traction. 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 diver- 

 gence. 



It has long been known that uterine contractions can be 

 induced by nervous stimulation. Thus Serres ^ showed that 

 irritation of the spinal cord in the lumbar region excited the 

 uterus to contract, and later investigators have obtained 

 similar results.^ Rohrig ^ showed that asphyxia which may 

 bring about uterine contractions (and abortion in the preg- 

 nant condition) cannot do so if the lumbar cord is destroyed. 

 Frankenhauser * and Korner ^ discovered that the efferent 

 nerve fibres left the lumbar region of the spinal cord, and after 

 traversing the sympathetic, the inferior mesenteric ganglia and 



' Serres, Anatomie Oomparee du Oervea, 1824. 



" Budge, " Ueber das Centrum genitospinale des Nervus sympathetious," 

 Virchow's Archiv, vol. xv., 1858. Riemann, "Einige Bemerknngen fiber 

 die Innervation der Gebarmutter," Arch./. Oynak., vol. ii., 1871. 



' Robrig, " Experimentelle Untersucbungen fiber die Pbysiologle der 

 Uterusbewegung," Virchow's Archiv, vol. Ixxvi., 1879. 



' Frankenhauser, " Die Bewegungsnerven der Gebarmutter," Jenaische 

 Zeitschr.f. Med., vol. i., 1864. 



' Korner, Studien d. Phys. Institute zu Breslau, 1865. 



