CASTRATION OF THE STALLION 17 



Anatomy — A comprehensive knowledge of the anatomy of the inguinal 

 and scrotal regions is imperative if a man is ever to be anything like a 

 thrilling success in performing the various necessary operations that are 

 to be described later. However, on account of the limited space at my 

 disposal it will be impossible to go into minute detail here. For complete 

 and detailed anatomical description the reader is respectfully referred to 

 Sisson's, Chanreau's, McFady can's, and Strangeways' textbooks on veteri- 

 narj- anatomy. 



Scrotum — This is a sac or bag made up externally of a layer of skin 

 which has been continued from the sheath, abdomen and flanks. This skin 

 is smooth, soft and hairless compared with the other portions of the in- 

 tegument. The scrotum consists of two parts divided by a longitudinal 

 raphe (median line). Below the skin is the dartos which forms the scrotal 

 tunic proper, and consists of thin elastic tissue and muscle. The dartos 

 is a continuation of the abdominal fascia. Under the dartos is the sper- 

 matic fascia which is a continuation of the external oblique muscle. This 

 muscle is attached to the external abdominal ring. Inside is the cremas- 

 teric fascia, an expansion of the eremaster muscle which passes through 

 the inguinal canal over the cord and surrounds the testicle. Deeper we 

 have the funnel-shaped infundibuliform fascia which originates at the in- 

 ternal abdominal ring. This fascia is simply a sheath over the testicle, the 

 cord and their tunics. 



Inguinal Canal — This canal is situated obliquely between the crural 

 arch and the internal oblique muscle. The arch forms its posterior, and 

 the muscle its anterior wall. It is compressed laterally, and through it 

 pass the spermatic cord and the pudic arterj^ Its external orifice is termed 

 the external abdominal ring. This ring is oval in shape and its direction 

 is backward and upward. The internal abdominal ring is a small aperture 

 in the abdominal wall and is .situated at the uppermost part of the inguinal 

 canal, which is eight to ten inches above the external abdominal ring. The 

 contents of the inguinal canal pass through the internal abdominal ring 

 in making their exit from the abdominal cavity. 



Sheath — The sheath is a loose conglomeration of skin extending from the 

 scrotum forward, and contains the free portion of the penis. The anterior 

 loose double fold of the sheath is known as the prepuce or foreskin, which 

 is corrugated to accommodate the penis during erection and protrusion. 

 Opening into the sheath are ducts from the glandule odoriferffi which se- 

 crete an odorous matter peculiar to the sheath. The sheath is suspended 

 from the abdominal walls by suspensory ligaments. 



Spermatic Cord— The testicle is suspended in the scrotum by the sper- 

 matic cord which migrates through the inguinal canal from the abdominal 

 cavity to the scrotum. The following structures enter into its formation: 



