96 ORGANS OF GENERATION. 



its cavity, and contains a small quantity of serous halitus, which 

 allows the opposed surfaces to glide freely upon one another. Its 

 exterior connexion with the dartos is so slight that it may be 

 withdrawn without dissection, with the exception of an adhesion 

 at the lower end of the testis arising from the remains of the gu- 

 bernaculum: in such case, however, it still continues to be in- 

 vested by the tunica vaginalis communis, from which it can only 

 be removed by a special dissection. 



The Tunica Albuginea is the proper coat of the testicle, is in 

 immediate contact with its glandular structure, and serves to 

 maintain its shape, as well as to protect it from pressure. From 

 its internal surface proceed many membranous, horizontal fibres, 

 which form partial partitions of its cavity (jSeptulce Teslis) and 

 incline towards its posterior part, where they terminate in a lon- 

 gitudinal projection, called Corpus Highmorianum. The latter 

 is of a prismatic shape, somewhat broader above than below, 

 and is of but little consequence, except that it was once errone- 

 ously supposed to be a sinus, into which the seminiferous tubes dis- 

 charged. Sir Astley Cooper proposes to call this the mediastinum 

 testis, and considers the Corpus Highmorianum as being formed 

 by an inflection of the tunica albuginea. The Septulse Testis, 

 he asserts, really envelop the seminiferous tubes, by forming bags 

 which support, confine, protect, and nourish the tubular struc- 

 ture of the testis.* The albuginea is perforated by several fo- 

 ramina along its posterior margin, where there is a deficiency 

 of tunica vaginalis for the passing of excretory ducts and blood 

 vessels. 



This membrane is dense, strong, white, and fibrous, resem- 

 bling in structure the tunica sclerotica of the eye, and the dura 

 mater of the brain. Sir A. Cooper considers the tunica albugi- 

 nea as consisting of two layers which can be readily separated 

 by dissection, excepting in front; the outer layer is the fibrous 

 one, while the internal one, which he calls Tunica Vasculosa, 

 has the spermatic arteries and veins ramifying upon it. They 

 are rendered very distinct from each other by a minute injec- 

 tion.t 



* Observations, &c. on the Testis, p. 14. London, 1830. 

 fid. 



