ANIMAL CASTBATION. 



87 



inguinal canal, through the muscular portion of the 

 small oblique, near the posterior „ 



border and as far as possible from 

 the median line. It is advantageous 

 to enlarge the inferior inguinal ring 

 by making outward an incision, 5 or 

 10 centimeters long, on its aponeu- 

 rotic coat, so as to expose the re- 

 gion where the small oblique has a 

 thick layer. The abdominal wall 

 may be perforated, with the index 

 and medium fingers brought together 

 or with a thin, blunt metallic per- 

 forator (Fig. E). 



Towards the end of an inspiration 

 from the animal, when the abdominal 

 wall is raised, apply perpendiciilarly 

 upon it, in the direction of the mus- 

 cular fibres, the fingers or tho blade 

 of the instrument and push them 

 through it with sudden i:)ressure. 

 Generally, at the first effort, the 

 muscle, aponeurosis and peritoneum 

 are divided ; sometimes, however, 

 the serous membrane resists and a 

 second push is necessary to complete 

 the perforation. If this has been 

 properly executed, the solution of 

 continuity is narrow and regular; it 

 is a simple slit by separation of the muscular fibres. 



Third Step. — Searching the Tes^/cfe.— Through this 



Perfokato?.. 



