Conflicting reports in the recent literature indicate that developing amphibian teeth have mesodermal enamel, or conversely that amphibian teeth have ectodermal enamel.
Careful comparisons were made of developing teeth in amphibians with teeth in comparable developmental stages from the fetal pig and alligator lizard, using hematoxylin and eosin, Mallory's azan, Soule's gold chloride, Schmorl's thionin, and toluidine blue stains. A similar comparison of developing amphibian, reptilian and mammalian teeth was made under ultra-violet light and a UG-1 filter to produce autofluorescence. The histochemical and fluorescent comparisons combined with morphological similarities strongly indicate that the development of enamel in mature amphibians is identical to that found in reptiles and mammals. The presented evidence shows that in adult amphibians the enamel develops from ameloblasts formed from the inner enamel (dental) epithelium of the enamel organ and is "ectodermal enamel!'
<br />The author wishes to express his gratitude to Mrs. Renee Z. Bertolino for her technical assistance.