FINE-STRUCTURE OF MERKEL CORPUSCLES IN THE LINGUAL MUCOSA OF JAPANESE-QUAIL, COTURNIX-COTURNIX-JAPONICA

By electron microscopy, these corpuscles were found exclusively in the connective tissue just beneath the dorsal epithelium near the lateral margin of the tongue. Each consisted of 4-8 Merkel cells and flattene d nerve terminals arranged alternately. The Merkel cell was characteri zed by dense-cored granules, with a diameter ranging from 120 to 180 n m, throughout the cytoplasm. The functional significance of the avian Merkel cell, i.e. a mechanoreceptor cell or a trophic cell with the ax on, still remains enigmatic, as is the case with Merkel cells of other vertebrates.