ON VASOLIGATION, ETC. 283 



Post-operative 



period. Result. 



4. 14 days. Normal spermatogenesis in right testis. 



5. 17 days. Seminal epithelium completely disorganised and reduced in right 



testis. Left, normal. 



6. 20 days. Sperms from right vas deferens dead and motionless. In sections 



very slight signs of abnormality in a few tubules, otherwise 

 normal spermatogenesis. 



Marginal membrane ligatured on left side. Right testis detached from scrotum 

 and fixed to abdominal wall by ligature passing through gubernaculum. 



Post- operative 



period. Result. 



7. 16 days. Right testis atrophied and degenerate, only about half the size of 



the other, seminal epithelium completely disorganised. Left 

 testis functional, the ligature loose. 



Of the first six experiments, leaving out of consideration that in which the other 

 testis was removed from the scrotum to the abdomen because in that the ligature 

 was found to be loose, there was complete disorganisation of the seminal epithelium 

 in two, the first and fifth ; normal spermatogenesis in one, the fourth ; and slight 

 traces of disorganisation in a few tubules in three. Careful examination by sections, 

 and cleared preparations showed nothing in the marginal membrane but lymphatic 

 channels and small blood-vessels. It is probable that the injurious effects of ligature 

 of this membrane are due to varying degrees of injury to the tubules of the apex of 

 the caput epididymis to which the membrane is attached. 



The following is a list of the experiments in which the true vasa efferentia were- 

 ligatured : — 



Experiments on ligation of vasa efferentia. 



Vasa efferentia ligatured on left side, marginal membrane on the right. 

 Post-operative 



period. Result. 



1. 6 days. Testis of each side flaccid and reduced in size. In sections,. 



seminal epithelium in both testes disorganised, no spermato- 

 genesis. 



Vasa efferentia ligatured on right side only. 



Post-operative 



period. Result. 



2. 14 days. Seminal epithelium completely disorganised. Weight of right. 



testis 1.535 gins., left 2.200 gins. 



3. 14 days. Seminal epithelium completely disorganised. 



4. 7 days. Seminal epithelium completely disorganised, but not so much 



reduced. No spermatogenesis. 



These experiments show that closure of the lumen of the vasa efferentia causes, 

 complete disorganisation of the seminal epithelium in seven days, or even in six days, 

 assuming that the evidence of the first experiment is valid. In the other three the- 

 left testis served as control, and showed perfectly normal spermatogenesis. As there 

 was no interference with the blood circulation in the testis, the effect must be due to 

 increase of pressure within the tubules. It follows therefore that when the vas 

 deferens only is ligatured, the absence of injurious effect is due to the fact that the 

 great space contained in the long coiled tube of the epididymis prevents this increase 

 of pressure in the seminal tubules, the epididymis acts as a reservoir for the semen 

 and becomes greatly distended in consequence. The conclusion is that when the 

 distension and pressure increase to a certain point within the epididymis, absorption 

 of semen is increased, an equilibrium is reached, and no further rise of pressure occurs. 



