The sulfatides and some histochemical correlations of the lachrymal glands involved in salt secretion in Chelonia.

High concentrations of sulfolipids (four fractions having different hexose/sulfate ratio), intense enzyme activity (ATPase, oxoreductases) and evidence of mucines (staining with PAS and Alcian blue) in intercellular spaces were found in the lachrymal glands of Caretta caretta and Malaclemys terrapin adapted to sea water. In addition, the supranuclear region of the gland cells in Malaclemys terrapin is filled with mucin granules. These biochemical and histochemical observations indicate that these glands have a function in salt secretion in both species and are also consistent with a function of mucous secretion exclusively in Malaclemys terrapin. Limited signs of hypotrophy are not accompanied by changes in concentrations of sulfolipids in Malaclemys terrapin adapted to fresh water; only the reactions for enzyme activities are less intense. The mucous secretion is not affected, whereas, in correlation with changes in salt secretion, the change in ATPase activity is mot conspicuous. The correlations between the different components of the gland and salt secretion are compared with salt glands of birds and elasmobranchs.