Quarterly Journal of Microscopical Science, Vol s3-104, 197-205, Copyright © 1963 by Company of Biologists

A Cytological and Cytochemical Study of the ‘Epithelial Body’ on the Carotid Artery of the Lizards, Trachysaurus Rugosus and Tiliqua Occipitalis

¹ Department of Zoology, University of Melbourne, Melbourne, Victoria, Australia

Epithelial body III of Tiliqua occipitalis and Trachysaurus rugosus has been the subject of a histological and cytochemical investigation with the object of making a comparison with the mammalian parathyroid gland. The cytochemical reactions of the reptilian chief cell are similar to those of the mammalian ‘pale principal’ cell. On the basis of a series of cytological and cytochemical changes a secretory cycle commencing with the chief cell and culminating in the water-clear cell is postulated. Two further cell types distinguished as the dark cell and the ‘epithelial’ cell have been described in the reptilian epithelial body. The significance of these two cell types is discussed. There is some evidence suggesting that true sinusoids invest the cellular cords. There is no evidence, with the technique used, that the gland cells are innervated. It is suggested that the general histology is comparable to that of the mammalian parathyroid gland.