Transmission electron micrograph of lysosomes in the interstitial cells of Leydig in the testis of the domestic boar. Additional examples of laminated inclusions in lysosomes are illustrated here in micrographs from Leydig cells which, like other steroid-secreting cells, are rich in lysosomes. The clear spaces interposed among the lamellae are negative images of thin tabular crystals of unknown nature that have been dissolved in the course of specimen preparation.