978 



TESTICLE (NORMAL ANATOMY). 



mentous cords from the inner surface of the 

 tunica albuginea. I have not been able to 

 make out any such ligamentous processes 

 passing into the substance of the testis, as are 

 represented in Sir A. Cooper's work (part i. 

 pi. 2. fig. 3), which I have no doubt is an ex- 

 aggerated view of the preparation from which 

 it was taken. The cords described appear to 

 me to consist chiefly of blood-vessels sup- 

 ported by slight fibrous processes from the 

 tunica albuginea and areolar tissue. In a well- 

 injected testicle very little tissue of the nature 

 of ligament can be found between the lobes. 

 The secreting structure of the testicle, like the 

 texture of many other glands does not possess 

 much common sensibility. When exposed in 

 disease it may be probed and injured with the 

 forceps without pain. 



Tubuli Seminifcri. These tubes, which 

 form by far the greatest part of the bulk 

 of the glandular structure of the testicle, 

 are very numerous, and radiate from all parts 

 of the circumference of the organ towards 

 the mediastinum, making numberless con- 

 volutions which progressively diminish as 

 they approach the rete testis. Two or 

 more of the tubuli, being collected together 

 and invested by a common tunic of con- 

 densed areolar tissue, form a lobe or lobule of 

 a conical form, its apex terminating at the 

 corpus Highmori. The lobes thus formed are 



Fig. 631. 



T7ie lobes attached to the mediastinum, but artificially 

 separated from each other. (From a preparation 

 in the Hunterian Museum, formerly in Sir A, 

 Cooper's collection.) 



not entirely distinct, but communicate with 

 neighbouring lobes : the processes investing 

 them are therefore incomplete, and the lobes 

 cannot be separated from each other without 

 division of some of the seminiferous tubuli. 

 Krause estimates the number of the lobes as 

 varying from 404 to 484.* The tubuli are of 

 a white colour and uniform size, but their 

 calibre differs in different subjects, and varies 

 a good deal according to the age of the subject 

 and the state of activity of the testicles, being 

 larger in young adults and when distended 

 with semen, than in old persons and when the 

 gland is in a state of rest. The size of the 

 ducts also often differs in the two testicles of 

 the same subject. In general the calibre of 

 the tubuli corresponds to the size of the tes- 



* Mliller, Archiv. fur Anatomic, 1837, s. 22. 



tide. Observers do not exactly agree in 

 their estimates of the diameter of the tubuli. 

 The average diameter of the uninjected canal 

 is estimated by Miiller at -^ of a line ; by 

 Lauth * at T |^ of an inch. Krause found the 

 tubuli, when filled with semen, to measure 

 about -JL. of a line, and in old men and youths 

 Jg-. Huschkef estimated the ordinary thick- 

 ness of the whole tube from -^ to ^ of a line, 

 and that of the walls from t^ to ^y. Owing 

 to the stoutness of the basement membrane, 

 the thickness of the walls of the tubes is con- 

 siderable as compared with the secreting ducts 

 of other glands, and this accounts for the 

 tubes being able to resist the pressure of a 

 column of mercury in injections. Monro 

 reckoned the number of the seminiferous 

 tubes at 300 ; Lauth made the average num- 

 ber 840, and he estimated the mean length of 

 all the ducts united at 1750 feet. He found 

 the individual ducts to vary in length, the 

 mean being 25 inches. Krause estimated 

 their entire length at 1015 feet. The mem- 

 brane composing the tubuli is continuous 

 with the mucous surface of the genito-uriuary 

 system. It is lined with epithelium, and the 

 spermatozoa are developed from the epi- 



Fig. 632. 



Glandular structure of the testicle, displayed by mer- 

 curial injection. (After Lauth.) 



a a a, glandular substance of the testicle subdi- 

 vided into lobes, each lobe being composed of con- 

 voluted tubuli closely packed ; b, rete testis ; c, vasa 

 efferentia ; d, inflected part of the vasa efferentia 

 forming the coni vasculosi ; e, dilatations of the 

 efferent vessels ; /, body of the epididymis ; g, tail 

 of the epididymis ; h, vasculum aberrans ; i, in- 

 flected part of the vas deferens ; k, straight part of 

 the duct. 



* Mem. de la Societe' d'Hist. Nat. de Strasbourg, 

 t. i. 



f Encyclopedic Anatoinique, t. v. p. 347. 



