136 THE TESTES, BY V. LA VALETTE ST. GEORGE. 



tolerably regularly arranged and very pale circular nuclei. We 

 may therefore consider it to possess a lamellar structure, and 

 to be composed of flat scales with flattened nuclei." 



Frey* distinguishes two layers, a structureless membrana 

 propria, and an external dense tunic of a fibrous and striated 

 nature, with elongated nuclei, and appends illustrations taken 

 from the testes of the Calf and of Man. 



According to v. Hessling,f the tubuli seminiferi are composed 

 of a structureless glandular membrane, or membrana propria, 

 with a thickness of 1 JJL ; and externally, of a finely striated 

 lamellated tunic of connective tissue with elongated roundish 

 nuclei, which is 3 ju in thickness, and is sharply differentiated 

 from the remaining interstitial connective tissue. 



KollikerJ terms the investment of the tubules a fibrous 

 membrane, on the inner surface of which a membrana propria 

 can easily be demonstrated by the action of caustic potash. 



Letzerich admits for the Kabbit only a structureless 

 membrane, with pale elliptical nuclei. 



I myself found in a one-year-old child, after maceration of 



Fig. 168. 



Fig 168. Portion of a seminiferous tubule from the embryo of a 

 Cow. a, Adventitia ; 6, propria. 



the testis in acetic acid, that the contents of the tubules were 

 surrounded by a very fine structureless membrane, external to 

 which was a thick adventitia, with numerous nuclei. 



* Handbuch der Histologie, p. 607. 

 t Grundzilge der Gewebelehre, p. 328. 

 t Handbuch der Gewebelehre, p. 521. 

 Virchow's Archiv, Band xlii., p. 570. 



