Mucopolysaccharide histochemistry of the avian tongue. Histochemical features of the lingual glands in Larus ridibundus (L).

From the histochemical analysis carried out on the tongue of Larus ridibundus (L.), it has been possible to establish that it is covered by thick stratum corneum on the dorsal surface and shows both in the anterior and posterior portions lingual glands, which histologically consist of aggregates of branched tubules. These glands exhibit identical histochemical reactions which show the presence of neutral mucopolysaccharides, sulfated and unsulfated acid mucosubstances and hyaluronidase-resistant sulfomucins. The acid mucosubstances have no connection with sialic or hyaluronic acid. The seeming absence of sialomucins which may probably not be due to the feeding habits of the animal, could be referred to the phylogenetic aspects of some markedly heterogeneous glycoproteins.