732 



GENERATION AND DEVELOPMENT. 



Fig. 212.* 



the main trunk of the secreting tube, when followed back 

 to its origin, is found to pass to the lower part of the 

 epididymis, and assumes there a much less diameter with 

 a very tortuous course : with its various convolutions it 

 forms first the mass named ylobus minor, then the body, and 

 then the globus major of the epididymis. At the last-named 

 part, the duct divides into ten or twelve small branches, 

 the convolutions of which form coniform masses, named 

 coni vasculosi ; and the vessels continued from these, the vasa 

 efferentia, after anastomosing, one with another, in what is 

 called the rete testis, lead finally through the tubuli recti or 

 vasa recta to the tubules which form the proper substance of 

 the testicle, wherein they are arranged in lobules, closely 

 packed, and all attached to the tough 

 fibrous tissue at the back of the testicle. 

 The seminal tubes, or tubuli seminiferi, 

 which compose the proper substance 

 of the testicle, are fine thread-like 

 tubules, formed of simple homogene- 

 ous membrane, measuring on an 

 average -lo-th to -J-,-th of an inch 

 in diameter, and lined with epithe- 

 lium or gland- cells. Rarely branching, 

 they extend as simple tubes through 

 a great length, with the same uniform 

 structure, and probably terminate 

 either in free closed extremities or in 

 loops. Their walls are covered with fine capillary blood- 

 vessels, through which, reckoning their great extent in 



* Fig. 212. Plan of a vertical section of the testicle, showing the 

 arrangement of the ducts. The true length and diameter of the ducts 

 have been disregarded, a, a, tnbuli 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 t mediastinum. 



