THE MORPHOGENESIS OF CIRCUMVALLATE PAPILLAE AND THE DIFFERENTIATION OF TASTE-BUDS IN THE CAT IN ONTOGENY

The development of circumvallate papillae, taste buds and associated s tructures, i. e., other types of lingual PaPillae, gll. gustatoriae an d their ducts, was studied in the tongues of feline foetuses 31, 40 an d 48 days old, kittens one day old and adult cats. Circumvallate papil lae were commenced at 40 weeks of foetal age, the encircling furrow an d the ducts of gll. gustatoriae developed at 48 days. Fungiform and fi liform papillae appeared later. Taste buds differentiated from day 31 of foetal development. They were first found in the epithelium of the dorsal surface of circumvallate papillae; in the wall epithelium they appeared at 48 days. At the beginning, the cells constituting the buds were uniform in appearance, from day 48 it was possible to distinguis h their types. The number of differentiating buds increased within one papilla from day 40 of foetal development.