316 GENERATION. 



dal, the larger extremities presenting toward the surface, and 

 the pointed extremities situated at the mediastinum. 



Lining the tunica albuginea and following the mediasti- 

 num and the processes which penetrate the testicle, is a tu- 

 nic, composed of blood-vessels and delicate connective tissue, 

 called the tunica vasculosa. 



Lodged in the cavities formed by the trabeculae of con- 

 nective tissue, are the seminiferous tubes, in which the male 

 elements of generation are developed. These tubes exist to 

 the number of about eight hundred and forty in each testi- 

 cle, and constitute almost the entire substance of the lobules. 

 The larger lobules contain five or six tubes, the lobules of 

 medium size, three or four, and the smallest frequently en- 

 close but a single tube. 1 Each tube presents a convoluted 

 mass, which can frequently be disentangled under water, 

 particularly if the testicle be macerated for several months 

 in water with a little nitric acid. The entire length of the 

 tube, when thus unravelled, is about thirty inches, and its 

 diameter is from -gfa to y^j- of an inch. It begins by from 

 two to seven short, blind extremities and sometimes by anas- 

 tomosing loops. The csecal diverticula are found usually in 

 the external half of the tube, and their length is from -fa to 

 J- of an inch. The anastomoses are sometimes between the 

 tubes of different lobules, sometimes between tubes in the 

 same lobule, and sometimes between different points in the 

 same tube. 9 As the tubes pass toward the posterior portion 

 of the testicle, they unite into about twenty straight canals, 

 called the vasa recta, about -fa of an inch in diameter, which 

 penetrate the substance of the mediastinum testis. In the 

 mediastinum, the tubes form a close net-work, called the rete 

 testis; and, at the upper portion of the posterior border, 

 they pass out of the testicle, by from twelve to fifteen open- 

 ings, and are here called the vasa efferentia. 



Having passed out of the testicle, the vasa efferentia form 



1 SAPPET, Traite d'anatomie, Paris, 1874, tome iv., p. 601. 

 3 SAPPEY, loc. oil., p. 606. 



