Cytomorphosis of Human Testicular Cells 95 



Heretofore, the assumption that the crystalloids of Reinke 

 are protein has been based entirely upon their solubilities and 

 staining reactions as studied with the light microscope. The 

 present study presents additional evidence of their protein 

 nature in their rounded shapes and soft consistency, and it 

 provides the first visual demonstration of their large molecular 

 size and crystalline internal organization. It is apparent that 

 the crystals of Reinke are entirely different from the crystal- 

 loids of Spangaro and Lubarsch which are found in the epi- 

 thelium of the seminiferous tubules. 



In addition to the spindle-shaped interstitial cells and the 

 typical Leydig cells just described, many cells are observed 

 which appear to be intermediate between these two cell types. 

 These transitional forms have some of the cytological charac- 

 teristics of both. Thus, one may find bundles of delicate 

 filaments, typical of the spindle-shaped interstitial cells, 

 intermingled with numerous sub-microscopic vacuoles of 

 the sort commonly found in mature Leydig cells (Fig. 12). 

 The occurrence of such cells seems to support the contention 

 of earlier workers who postulated a gradual metamorphosis 

 of the spindle cells into mature Leydig cells. Moreover, the 

 striking variability among mature interstitial cells with 

 respect to the degree of vacuolation of their cytoplasm and 

 the abundance of their lipid droplets, pigment granules and 

 protein crystals, strongly suggests that they are of very 

 different ages or that they are in different phases of a cycle of 

 physiological activity. There seems to us to be little to sup- 

 port the contention that the Leydig cells clear themselves 

 of these accumulated inclusions and revert to spindle cells 

 (Rasmussen, 1932; Williams, 1950), but there is some reason 

 to suspect that they age and ultimately degenerate. Certainly 

 many cells are seen which are crowded with lipid and pigment 

 and have grossly swollen, distorted mitochondria, and some 

 of these also show large angular areas which, at high magni- 

 fication, are pale, poorly defined and devoid of visible internal 

 structure, as though they were "ghosts" of crystals which had 

 undergone dissolution. Although dependable criteria for the 



