OVUM-LIKE BODIES IN THE TESTIS 567 



Basement M e m b r a ii e . — The basement membrane of the 

 tubules presents a somewhat remarkable appearance (PL 20, 

 fig. 13). Between the basement membrane cells and the 

 epithelium is a layer, the substance of which is in some cases 

 almost amorphous and in others distinctly fibrous. Elongated 

 nuclei occur either within or central to this layer. Kudiments 

 of this structure are present in all the tubules. In some it 

 has become so thickened that the epithelial cells are compressed 

 into a small mass in the centre of the tubule, and in a few in- 

 stances are completely obliterated. The layer appears to be 

 white fibrous tissue in various stages of development and with 

 Van Gieson's and Mallory's stains takes on the same colora- 

 tion as does the intertubular fibrous tissue. It is presumably 

 formed by the cells of the basement membrane. 



The same phenomenon was observed in the human testis 

 (PI. 20, fig. 14). In this specimen the majority of the semin- 

 iferous tubules are completely filled with a lightly-staining 

 substance of gelatinous appearance bounded by the cells of 

 the basement membrane. Occasionally a small central space 

 containing cell debris remains. With Van Gieson's stain this 

 material takes on the acid fuchsin as does the white fibrous 

 tissue in other parts of the gonad. In some tubules fine fibres 

 can be distinguished in the amorphous matter. A similar 

 gelatinous layer invests groups of interstitial cells and the 

 tubules of the rete testis. In these latter cases the substance is 

 apparently produced by the neighbouring connective tissue cells. 



It would appear that increase in fibrous tissue is correlated 

 with colloid degeneration of the germinal epithelium. Large 

 quantities of fibrous tissue are conspicuous both in the goat 

 and in the rabbit, but not in the undescended testis of a cat 

 (to be described later) in which degeneration had only just 

 begun, nor in the testis of a pig in which spermatic tissue has 

 undergone fatty degeneration. Our explanation of this 

 correlation is that the colloid produced by the degeneration of 

 the germ cells has two possible fates : 



(1) It may form large colloid globules in the centre of the 

 lumen. 



