Developmental, histological and ultrastructural studies on the harderian gland of the Egyptian toad, Bufo regularis Reuss.

The present study shows that the Harderian gland of the toad Bufo regularis starts to appear during development at stage 57 concomitant with the development of the nictitating membrane. In the adult toad, the gland was found to be formed of one lobe and occupying the antero-ventral aspect of the orbital cavity. No anatomical differences were noted between the male and female glands. The histological and ultrastructural studies showed that the Harderian gland is a compound tubular gland composed of rounded tubules lined by a single layer of epithelial cells and having a meshwork of myoepithelial cells surrounding the gland tubules. Differences were observed in the epithelial cells of female and male toads Bufo regularis. While females have a dilated rough endoplasmic reticulum and several secretory granules throughout the cytoplasm, males have a compact rough endoplasmic reticulum and numerous secretory granules and vacuoles.