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



distended, and the continuity of the vas interrupted ; the ligature lies 

 in situ on the lower end of the upper segment of the duct. 



As an example showing the results of unilateral vasotomy combined 

 with unilateral castration, we may select the following : — ■ 



"Buff Orpington," about 8 weeks old. Nine months after the 

 operation the bird was thoroughly male, the comb and wattles being- 

 well developed, as well as the neck-hackles and sickle-feathers of the tail. 



Twelve months after the date of operation the spins were sharp. 

 On being put with a hen the bird immediately copulated, although it 

 had had no previous opportunity of approaching one. Eighteen 

 months after the operation it was killed. On dissection the right 

 testicle was found to be of full size, about 3*5 cm. in the longer 

 diameter ; the epididymis was slightly distended. A scraping from the 

 divided body of the gland revealed the presence of spermatozoa. The 

 lower segment of the vas was found to taper off and end quite dis- 

 tinctly about a quarter of an inch below the level of the testicle. The 

 noose of the ligature was covered with a thin layer of connective 

 tissue, and lay on the posterior surface of the organ. The position of 

 the ligature may be explained by «the general growth of the gland ; 

 this growth would naturally lead to an extension in all directions, and 

 that in the downward direction would, relatively to the testicle, raise 

 the site of the ligature. On the left side no trace of testicle was 

 found. Microscopic examination of the body of the testis from the case 

 of double vasotomy first cited shows the tubuli to be full of cells, and 

 spermatogenesis in high activity, all the typical histological pictures 

 being present. The same holds true of the right testicle from the case 

 of combined vasotomy and castration last detailed. 



These results offer a striking contrast to those following a double 

 castration when carried out upon the immature bird. Double castration 

 was performed through a lateral incision on each side, the testicle 

 being exposed to view, and afterwards carefully disconnected from its 

 attachments with fine forceps, and withdrawn. In ideal experiments 

 the gland was withdrawn entire ; in others rupture occurred during 

 the process of detachment, the organ being then removed piecemeal. 



Results of incomplete, canonisation. — In certain of our experiments it 

 happened that the testicle gave way during its detachment, and that 

 minute fragments were unintentionally left behind. Sometimes such 

 remnants, as told by subsequent dissection, were left in their normal 

 position ; at others they were dislocated and transplanted upon the 

 adjacent viscera, or abdominal wall. Under such circumstances the 

 cockerel assumed in different degrees the character of the male. 



The actual number of gland remnants left at such imperfect opera- 

 tions, and the position of the grafts resulting from their displacement, 

 varied considerably. Thus, in one case the dissection of the fully 



