GLANDULAR SUBSTANCE OF THE TESTIS. 969 



by Astley Cooper mediastinum testis. Projecting inwards from the back 

 of the testis, it extends from the upper nearly to the lower end of the 

 gland, and it is wider above than below. The firm tissue of which it is 

 composed is traversed by a network of seminal ducts, and by the larger 

 blood-vessels of the gland, which are lodged in channels formed in the 

 fibrous tissue. 



From the front and sides of the corpus Highmorianum numerous slender 

 fibrous cords and imperfect septa of connective tissue are given off in radiating 

 directions, and are attached by their outer ends to the internal surface of 

 the tunica albuginea at different points, so as to assist in maintaining the 

 general shape of the testicle, and enclose the several lobes into which the 

 substance of the testis is divided. The whole internal surface of the tunica 

 albugiuea is covered by a multitude of fine blood-vessels, which are branches 

 of the spermatic artery and veins, and are held together by a delicate 

 areolar web. Similar delicate ramifications of vessels are seen on the 

 various fibrous offsets of the mediastinum, upon which the blood-vessels are 

 thus supported in the interior of the gland. This vascular network, 

 together with its connecting areolar tissue, constitutes the tunica vasculosa 

 of Astley Cooper. 



The proper glandular substance of the testicle is a soft but consistent mass 

 of a reddish-yellow colour, which is divided into numerous small lobes of 

 conical form, with the larger ends turned towards the surface of the testicle, 

 and the smaller towards the mediastinum. The number of these lobes (lobuli 

 testis) has been estimated at 250 by Berres, and at upwards of 400 by Krause. 

 They differ iu size according to their position, those which occupy the middle 

 of the gland and reach its anterior border being longer and larger than the 

 rest. They consist almost entirely of small convoluted tubes, named tubuli 

 seminiferi, vascula serpentina, in the interior of which the seminal fluid is 

 secreted. Each lobe contains one, two, three, or even more of these con- 

 Fig. 677. PLAN OP A VERTICAL SECTION OP THE TESTICLE, Fig. 677. 



SHOWING THE ARRANGEMENT OP THE DlJCTS. 



The true length and diameter of the ducts have been dis- 

 regarded, a, a, tubuli senainiferi coiled up in the separate 

 lobes ; b, vasa recta ; c, rete vasculosum ; d t vasa efferentia 

 ending in the coni vasculosi ; I, e, g, convoluted canal of the 

 epididymis ; h, vas deferens ; f, section of the back part of 

 the tunica albuginea ; i, i, fibrous processes running between 

 the lobes ; s, mediastinum. 



voluted tubules, the coils of which, being but loosely 

 held together, may be more or less successfully un- 

 ravelled by careful dissection under water. Lauth 

 estimates their mean number to be 840, and the 

 average length two feet and a quarter. Their dia- 

 meter, which is uniform throughout their whole 

 course, is from ^-J-^th to yj th of an inch. They 

 present two kinds of convolutions, each tube having 



a fine and regular undulation, which gives a granular appearance to the 

 whole mass, and this undulating tube being again thrown into com- 

 plicated folds, which are compressed so as to be elongated iu the direction 

 of the lobule. The lobules are never quite distinct, for here and there 

 tubules are always to be found passing from each to those around ; and it 

 sometimes happens that tubules which are divided by a straight plane of 



