VAS DEFERENS. 319 



mon tube forming the ejaculatory duct, which opens into the 

 prostatic portion of the urethra. 



The walls of the vas deferens are thick, abundantly sup- 

 plied with vessels and nerves, and provided with an external 

 fibrous, a middle muscular, and an internal mucous coat. The 

 greater part of that portion of the tube which is connected 

 with the bladder is dilated and sacculated. The fibrous coat 

 is composed of strong connective tissue. The muscular coat 

 presents three layers ; an external, rather thick layer of lon- 

 gitudinal fibres, a thin, middle layer of circular fibres, and a 

 thin, internal layer of longitudinal fibres, all of the non-stri- 

 ated variety. By the action of these fibres, the vessel may 

 be made to undergo energetic peristaltic movements, and this 

 has followed galvanization of that portion of the spinal cord 

 corresponding to the fourth lumbar vertebra, which is de- 

 scribed by Budge as the genito-spinal centre. 1 



The mucous membrane of the vas deferens is pale, thrown 

 into longitudinal folds in the greatest part of the canal, and 

 presents numerous additional rugae in the sacculated portion, 

 these rugae enclosing little, irregular, polygonal spaces. The 

 membrane is covered with columnar epithelium, which is not 

 ciliated. In the sacculated portion, are numerous mucous 

 glands. 



Attached to the vas deferens, near the head of the epi- 

 didymis, is a little mass of convoluted and sacculated tubes, 

 called the organ of Giraldes, 3 or the corpus innominatum. 

 This body is from -J- to. of an inch long and -fa of an inch 

 broad. Its tubes are lined with cells of pavement-epithelium, 

 which are often filled with fatty granules. Generally, the 

 tubes present only blind extremities, but some of them oc- 

 casionally communicate with the tubes of the epididymis. 

 This organ has no physiological importance. It is regarded 



1 BUDGE, Lehrbuch der speciellen Physiologie des Menschen, Leipzig, 1862, S. 

 787. 



a GIRALDES, Recherches anatomiques sur le corps innomine. Journal de la 

 physioloyir, Paris, 1861, tome iv., p. 1, et seq. 

 151 



