52 



Messrs. S. G. Shattock and C. G-. Seligmann. [Dec. 14, 



the other suffices singly to bring about the full development of the 

 male characters. 



A careful dissection, carried out in all the cases of vasotomy examined 

 and cited, showed that the vas had been completely occluded; not 

 only was its continuity interrupted, but the noose of the ligature was 

 demonstrated on the end of each segment of the divided duct. The 

 epididymis after occlusion of the vas may become notably larger than 

 normal ; this is especially obvious in the lower end or globus minor, 

 and is to be ascribed to its over-distention with the secretion trans- 

 mitted from the body of the gland. 



Microscopic sections of the testis of the normal adult Herdwick 

 sheep and of that from the vasotomised animal of the same age and 

 killed at the same date, show similar histological pictures. The tubuli 

 are filled with epithelial cells, and in nearly every one spermatogenesis 

 is in progress.* 



Experiments upon Fowls. 



Even still more striking are the results of double vasotomy in the 

 cockerel of the common fowl. In the fully grown cock the exposure of 

 the vasa deferentia and their ligation is not particularly difficult, but 

 in the young bird it is otherwise ; and the results cited are limited to 

 those cases where careful dissection afterwards proved that this difficult 

 procedure had been successfully carried out, the continuity of the duct 

 being found interrupted, and the noose of the ligature discovered at 

 the site of operation. The method of proceeding was as follows : — 

 The vas is exposed is its course over the kidney by a curved incision 

 carried through the lateral wall of the abdomen ; the duct having been 

 ligatured as near to the testicle as possible, is then cut across a short 

 distance below the ligated spot, no ligature being placed on the lower 

 segment. The vas of the other side is afterwards similarly dealt with 

 through a second incision carried through the corresponding side of the 

 abdomen. Owing to the difficulties of this operation, vasotomy was 

 in some cases performed on one side only, the testicle of the other 

 being removed. The ansesthetic used was chloroform, and the 

 material of the ligatures, silk. 



The results of double vasotomy, or of one-sided vasotomy combined 

 with one-sided castration, are in all cases alike. When carried out 

 upon the young, immature, bird, or cockerel, the development of the 

 male characters proceeds without any notable interruption, and reaches 

 its full degree. 



The birds used in the experiments were so young that it needed an 



* It may be incidentally remarked that whilst in the castrated lamb the 

 prostate fails to grow, in those submitted to vasectomy the gland comes to equal in 

 taze that of the intact ram. The same is true of the vesiculae seminales. If one- 

 testicle is removed and the vas of the other ligatured and cnt across, the prostate, 

 and vesiculae acquire the full size, and this without asymmetry. 



