966 



MALE ORGANS OF GENERATION. 



In other instances, the peritoneal process remains altogether pervious, and the cavity 

 of the tunica vaginalis is continuous with that of the peritoneum. In such a case of 

 congenital defect, a portion of intestine or omentum may descend from the abdomen 

 into the inguinal canal and scrotum, and constitute what is named a congenital hernia. 

 Lastly, one or both testes may remain permanently within the abdomen, or their 

 descent may be delayed till after puberty, when it may occasion serious disturbance. 

 Retention of the testes in the abdomen (cryptorchismus) is, in many instances, the 

 accompaniment of arrested development of the glandular structure ; it is, however, a 

 peculiarity which is often present without impotence. 



In a few mammals, as the elephant, the testes remain permanently within the 

 abdomen ; in a much larger number, as the rodentia, they only descend at each period 

 of rut. The complete closure of the tunica vaginalis is peculiar to man, and may be 

 considered as connected with his adaptation to the erect posture. 



6. The tunica vaginalis. This tunic forms a shut sac, the opposite walls 

 of which are in contact with each other. Like the serous membranes in 

 general, of which it affords one of the simplest examples, it may be described 

 as consisting of a visceral and a parietal portion. The visceral portion 

 closely invests the greater part of the body of the testis, as well as the 

 epididymis, between which parts it recedes in the form of a pouch (digital 

 fossa), and lines their contiguous surfaces, and it adheres intimately to the 



Fig. 675. 



Pi*. 675. THE LEFT TUNICA 

 VAGINALTS OPENED. SHOW- 

 ING THE TESTIS, EPII>IDY- 

 MIS, &c. 



p, p, the cut edges of the 

 parietal tunica vagiaalis drawn 

 aside laterally, as well as above 

 and^ below ; t, the body of the 

 testicle ; e, the globus major 

 of the epididymis ; e', the 

 globus minor, near which, /, a 

 fold of the tunica vaginalis (or 

 ligament) passes from the 

 body of the testis to the side ; 

 in the upper part of the figure 

 the tunica vaginalis has been 

 slightly dissected off at the 

 place of its reflection on the 

 cord to show vd, the vas 

 deferens, and g, the organ of 

 Giraldes; G, the three small 

 nodules of this organ enlarged 

 about ten times, and showing 

 the remains of tubular struc- 

 ture within them. 



proper fibrous tunic of 

 the gland. Along the pos- 

 terior border of the gland, 

 where the vessels and 

 ducts enter or pass out, the 

 serous coat, having been 

 reflected, is wanting. 



The parietal or scrotal portion of the tunica vaginalis is more extensive 

 than that which covers the body of the testis ; it reaches upwards, some- 

 times for a considerable distance, upon the spermatic cord, extending some- 

 what higher on the inner than on the outer side. It also reaches downwards 



