INTERSTITIAL CELLS OF URODELE TESTIS 247 



Child ('97) has called attention to the occurrence of. similar 

 giant centrospheres in the ovarian stroma (interstitial cells) of 

 the dog and rabbit. Allen ('04) pictm-es them also in his figures 

 of the interstitial cells of the mammalian testis and ovar3\ 

 Champy ('13) describes them in the interstitial cells of the Euro- 

 pean tritons and axolotl. Their occurrence in interstitial cells, 

 therefore, is probably more or less common. 



Such giant centrospheres have been very carefully studied by 

 W. H, Lewis ('20), who finds them of frequent occurrence in 

 living mesenchyme cells of tissues cultivated in vitro. He found 

 that cells containing them die sooner than the more normal cells, 

 and concluded that their presence may be regarded as a degenera- 

 tive change. In my material, likewise, the giant centrospheres 

 are seen in the older rather than the younger, more active cells. 

 The arrangement of fuchsinophile granules and lipoid droplets 

 around them suggests the action of the centrosphere as a center 

 of metabolism — a dynamic center of the cell; nevertheless, the 

 accumulation of such material largely occurs before the centro- 

 spheres attain their maximal enlargement. Though the enlarged 

 condition doubtless indicates a regressive change, it does not 

 seem, in my material, to represent an irreversible degenera- 

 tion. Cells possessing giant centrospheres become included 

 between growing lobules of spermatogonia, where they may be 

 seen with their granules and lipoids partially absorbed and the 

 centrospheres more or less reduced, while their nuclei, still normal 

 in appearance, are more or less flattened. Some of these unques- 

 tionably revert to the stromal cell type; other cells whose 

 regressive changes have been more pronounced, may not be 

 able to do so, as the large number of degenerations late in the 

 season indicates (figs. 18 and 33). 



€. Final degeneration or reversion of the cells. The growth of 

 the regenerating lobules, which has proceeded slowly during 

 the winter, is greatly accelerated by the more favorable 

 conditions of the warmer spring months. As the lobules 

 extend farther and farther toward the periphery of the testis, the 

 degenerating lobules and interstitial cells come to occupy a pro- 

 portionately smaller space in that region. The degenerating 



