[Fine structure of the parathyroid gland of the fresh water turtle (Pseudemys scripta)].

The ultrastructural characteristics of parathyroid in fresh-water turtles (Pseudemys scripta) are studied during the four seasons of the year. The gland parenchyma consists of chief cells organized in solid cordons. No oxifil cell is seen in turtle parathyroid. The chief cells present seasonal variations in cytoplasmatic organization. These are essentially represented by: the presence of secretory granules, cilia with centriolar apparatus and microfilaments in autumn; middle and wide lipid vacuoles and glycogen particles in winter; light and dark chief cells in spring. The dates, described above, suggest that seasonal variations of parathyroid in fresh-water turtles can be correlated with ultrastructural parathyroid aspects of hibernant animals.