THE REPRODUCTIVE SYSTEM. 



641 



branches, the convolutions of which form coniform masses, named Coni 

 vasculosi; and the ducts continued from these, the Vasa efferentia, after 

 anastomosing, one with another in what is called the Rete testis, lead 

 finally as the Tubuli recti or Vasa recta to the seminal tubules, or form 

 the proper substance of the testicle. The epithelium lining the coni 

 vasculosi and vasa efferentia is columnar and ciliated; that of the rete 

 testis is squamous. 



The seminal tubules are arranged in lobules, separated from one 

 another by incomplete fibrous septa or cords, which pass from the front 

 of the tunica albuginea internally to a firm incomplete vertical septum 

 of thick extending fibrous tissue at the posterior border, from the upper 



FIG. 429. 



FIG. 430. 



FIG. 429. Plan of a vertical section of the testicle, showing the arrangements of the ducts. 

 The true length and diameter of the ducts have been disregarded, a, a, tubuli seminiferi coiled up 

 in the separate lobes; 6, tubuli recti or vasa recta; c, rete testis; d, vasa efferentia ending in the 

 coni vasculosi; I, e, g, convoluted canal of the epididymis; h, vas deferens; /, section of the back 

 part of the tunica albuginea; i, i, fibrous processes running between the lobes; s, mediastinum. 



FIG. 430. Section of the epididymis of a dog. The tube is cut in several places, both trans- 

 versely and obliquely; it is seen to be lined by a ciliated epithelium, the nuclei of which are well 

 shown, c, connective tissue. (Schofield.) 



to near the lower part, called the corpus Highmori, or mediastinum tes- 

 tis. Through this very firm fibrous tissue pass the seminal tubes from 

 the vasa recta. Th0 tunica albuginea is covered by a very fine plexus of 

 blood-vessels internally, derived from the spermatic vessels. The fibrous 

 cords which may contain unstriped muscle are also covered with a simi- 

 lar capillary plexus. 



The Seminal Tubes. The seminal tubes, or tubuli seminiferi, 

 41 



