74 



TOPOGRAPHICAL ANATOMY OF THE 



testis, is a matter of controversy. Seeing, however, that the f^uber- 

 naculum is attached by one end to the caudal extremity of the testis, 

 and is fixed in the inguinal region by the other, it is reasonable to 

 suppose that in some measure, at least, the testis is guided in its 

 descent by the gubernaculum. 



The tail of the epididymis is the first object to enter the processus 

 vaginalis. Thereafter follow the testis and its mesorchium. 



The descent of the testis is frequently complete at the time of 

 birth; but the inguinal ring (the neck of the processus vaginalis) being 



Skin 

 Tiinicn dartos. 



M. creniaster extcrnus. 

 Ductus deferens 

 Ei)ididyniis. 



Sinus epididymidis 



Fibrous layer of 

 tunica vaginalis. 



• Testis. - 



Penis. 



Urethra. 



Septum scroti. 



Serous layer of tunica 

 vaginalis. 

 Visceral serous membran 



Raphe scroti. 

 Fig. 32. — Vertical section through the ])enis, scrotum and testis. Diagrammatic. 



wide at this time, the testis may be withdrawn into the inguinal canal 

 or into the abdomen, and not find a permanent residence in the scrotum 

 until several months after birth. In some instances the testis is per- 

 manently retained in the abdomen or (more rarely) in the inguinal 

 canal. This condition of malposition is known as cryptorchism. 



Dissection. — A longitudinal incision should be made through one of 

 the testis, entering the knife at the free ventral border, and carrying 

 the incision through the organ to the dorsal border. The other testis 

 may be sectioned transversely. 



Immediately underneath the serous covering of the testis there is a 

 whitish, resisting tunica alhuginea,^ about 2 mm. in thickness. In 

 1 Albus [L]., wliite. 



