XXXII.] TISSUES OF REPRODUCTION. 343 



/. The vasa recta ; the tubes have a single 

 layer of cubical or flattened cells. 



g. The rate testis ; the membrana propria of the 

 tubes disappears, the epithelium is rather 

 more flattened than in the vasa recta. 



h. The vasa efferentia and canal of the epi- 

 didymis ; 



a. The external fibrous coat. 



/8. Inside this a coat of circularly arranged 

 unstriated muscle. 



7. The epithelium consisting of columnar 

 ciliated cells with some small cells 

 between or outside their peripheral 

 ends near the basement membrane. In 

 the canal of the epididymis the ciliated 

 columnar cells are long and slender. 

 Masses of spermatozoa may sometimes 

 be seen in the lumina of the tubes. 



3. Cut a transverse section of the vas deferens and 

 compare with the sections of the canal of the 

 epididymis. 



a. The wall is very much thicker, this being 

 chiefly due to a great increase in the muscular 

 coat; there is a longitudinal muscular coat 

 outside the circular coat, 



h. The epithelium consists of non-ciliated colum- 

 nar cells with one or more layers of small 

 peripheral cells ; between the cells and the 

 muscular coat is a layer of fine connective 

 tissue Cmucous coat). 



