FURTHER OBSERVATIONS ON THE FINE STRUCTURE OF THE LEYDIG CELLS OF LACERTA SICULA SICULA RAFINESQUE DURING THE ANNUAL CYCLE AND AFTER TEMPERATURE CHANGES

SUMMARY The fine structure of the Leydig cells of Lacerta sicula sicula Ra- finesque is described for four different groups of animals: (i) normal summer specimens; (ii) normal autumn specimens; (iii) winter specimens kept at a temperature of 28°C; (iv) spring specimens kept at a temperature of 4°C. The normal summer and autumn animals shows, with the exception of the mitochondria, the same ultrastructural features already seen in the spring ones, i.e.: abundant smooth endoplasmic reticulum (S.E.R.), lipid droplets, lysosomes and filaments. The mitochondria, however, have tubular cristae in the summer specimens, but laminar ones in the autumn animals. The winter specimens kept at 28°C, when compared with the control animals, show a more abundant cytoplasm with a prominent S.E.R., numerous lipid droplets and mitochondria with tubular cristae, i.e. a remarkable renewal of the secretory activity. The interstitial cells of the spring lizards kept at 4°C are smaller than the control ones and their cytoplasm is...