Comparative tongue histology and scanning electron microscopy of the diamondback water snake natrix rhombifera and black rat snake elaphe obsoleta reptilia serpentes colubridae

and a muscularis. The mucosa contained a covering of non-keratinized stratified squamous epithelium and a tunica propria which consisted of dense fibrous connective tissue. The muscularis was composed of striated muscle fibers arranged longitudinally, transversely and sagitally. The tongue was enclosed by a sheath containing mucous glandular tissue and striated muscle fibers. No chemo-sensory structures were discerned. Differences between the species included distribution of melanin, number of dorso-lateral ridges and amount of glandular material. The SEM study showed modified epithelial cells in the forked region of the tongue. These cells were covered by numerous projections called microfacets which in the black rat snake were circumscribed by regularly spaced pores. These structures are thought to be responsible for transport of chemical molecules to Jacobson's organ.