Interstitial testicular cells of the lizard Lacerta muralis brueggemanni during the seasonal cycle

We have studied the fine structure of interstitial cells during the annual spermatogenic cycle in the testis of the lizard Lacerta muralis, (summer, autumn and winter) in order to correlate the morphology of the interstitial cells with the spermatogenic cycle. The results support the hypothesis that differentiated Leydig cells are always present whether in the nuptial, post-nuptial or hibernating period; the differences consisting in seasonal variations of their lipid content. Further, a peculiar interstitial cell, the "fusiform steroid-secreting" cell, has been described.