SPERMATIC DUCTS. 



233 



layer (adventitia) of connective tissue containing elastic fibres 

 and longitudinal smooth muscle cells (m. cremaster internus). 

 The terminal part of the vas deferens is dilated to form an 

 ampulla, which is lined with stratified columnar epithelium, 

 containing branched gland tubules with cubical or cylindrical 

 epithelium. 



FIG. 180. 



^--^Blood-vessels 



- Adventitia 



Ciliated 

 epithelium 



-"Tunica propria 

 .JSnbmucosa 



_ Circular muscle 

 layer 



Longitudinal 

 muscle 

 layer 



Cross-section of a human vas deferens. X 37. 



The structure of the seminal vesicles (vesiculse seminales) is 

 not essentially different from that of the ampulla. These are 

 glandular sacs, and may be considered among the accessory 

 sexual glands. 



The ejaculatory duct (ductus ejaculatorius) is lined with 

 stratified cylindrical epithelium. Like the vas deferens, its 

 walls show two main coats of smooth muscle, as well as a 

 thinner layer inside. 



Certain other structures must be mentioned, which are only 

 remains of embryonic organs. The paradidymis (organ of 

 Giralde), which consists of a few blind tubules lined with a 



