THE TESTICLES. 97 



Of the Minute Structure of the Testicle.* The glandular por- 

 tion of the testicle consists in a congeries of convoluted tubes 

 (Tubuli Seminiferi) amounting to 300, according to Dr. Munro; 

 and whose aggregate length is 5208 feet. The diameter ofeach 

 one does not exceed one two-hundreth part of an inch, and its 

 length is somewhat short of seventeen and a half feet. These 

 tubes form convolutions or hanks, the threads of which are ser- 

 pentine, very much like the thread of a ravelled stocking; and 

 are held together by a delicate cellular substance easily softened 

 by maceration. Each tube forms of itself a hank or lobule, which 

 is kept distinct from the adjacent ones by the septulae or parti- 

 tions of the albuginea, and may be easily picked out from them. 

 Their extreme tenuity and delicacy of structure cause them, 

 when well macerated, drawn out with a pin, and then suspend- 

 ed in water, to resemble a tangled skein of fine silk. 



The tubuli seminiferi finally terminate in straight tubes, called 

 the Vasa Recta, which unite near the centre of the testicle in a 

 somewhat complicated arrangement, obtaining the name of the 

 Rete Vasculosum Testis. From the latter there proceed from 

 twelve to eighteen ducts (Vasa Efferentia) which go upwards 

 and backwards to penetrate the corpus Highmorianum and the 

 tunica albuginea. Each of these vasa efferentia is then convo- 

 luted upon itself into a conical body, called Conus Vasculosus, 

 which presents its base backwards. Each cone, at its base, has 

 its tube entering successively into the tube of which the Epi- 

 didymis is formed. 



Notwithstanding the extreme tenuity of these several ar- 

 rangements in the excretory ducts of the testicle, they may be 

 entirely filled with quicksilver from the vas deferens; but the 

 task is one of great difficulty, and rarely succeeds. 



The epididymis is the prismatic arch which rests vertically 

 on the back of the testicle, and adheres to it by the reflection 

 of the tunica vaginalis. It is enlarged at both ends, the upper 

 of which, being formed by the Coni Vasculosi, is called the 

 Globus Major, and the lower enlargement is the Globus Minor. 

 It is formed of a single convoluted tube, of the fourth of a line 

 in diameter. After this tube has got to the lower end of the 



* Hunter, Med. Comment, p. 1. 1777. Albinus, Acacl. Annot. Lib. ii. Loder, 

 Tab. Anat. Ruysch, Thes. Anat. iv. Haller, Op. Min. torn. ii. Alex. Munro, de 

 Testibus, Ed. 1755. 



VOL. II. 10 



