Fig. 2
Morphological comparison between the dorsal warts and the parotoid macroglands. (a) Longitudinal section of a dorsal wart. Note the small number of poison glands (g). (b) Longitudinal section of a parotoid. The honeycomb-like structure is formed by a large number of subunits side by side, each one lodging a poison gland (g). (c) Transverse histological section of a dorsal wart, showing poison glands (g) and a mucous gland (*) highlighted in the insert. e, epidermis, d, dermis. (d) Transverse histological section of a parotoid macrogland showing the juxtaposed distribution of the poison glands (g). Note that the glands are larger in the centre of the structure and decrease towards periphery. The insert represents a high magnification of the area delimited by the rectangle, showing a duct obstructed by an epithelial plug (pl) surrounded by accessory glands (ac). Species: Rhinella marina (a, c, d) and Rhinella icterica (b). Staining: Mallory’s trichrome (c), toluidine blue-fuchsine (c, insert), haematoxylin-eosin (d)