494 THE REPRODUCTIVE SYSTEM , 



the lumen of the duct is narrow, as compared with its exceptionally 

 thick muscular wall. As elsewhere in the excretory canal of the testicle, 

 the lumen of the ductus deferens contains many spermatozoa. 



THE SPERMATIC CORD. The spermatic cord in its scrotal portion. 



FIG. 438. TRANSECTION OF THE DUCTUS DEFEKENS OF A DOG. 

 Hematein and eosin. Photo. X 104. 



in addition to the ductus deferens, contains a mass of connective tissue 

 in which are embedded the smooth muscle fibers of the internal cre- 

 master muscle, the spermatic artery, veins, and nerve plexus, and the 

 vessels of the pampiniform plexus. Closely associated with these con- 

 stituents is also the striated cremaster muscle proper. The whole is 

 invested by a reflection of the tunica vaginalis. 



The pampiniform plexus is a considerable group of venous spaces, 

 usually completely collapsed after death, which are characterized by 



