Abstract
The deposition of coccoliths, calcite-calcium carbonate-containing organic structures which align peripherally and are liberated into the environment by the primitive marine coccolithophorid chrysomonad protozoon Hymenomonas Mary Parke 156, follows the pathways of biphasic biologic mineral deposition without biochemical evidence of sulfur-containing polysaccharides. Tinctorial and autoradiographic evidence for the participation of sulfur-containing carbohydrate moieties is presented. Nutritional conditions and addition of inhibitors, which have been shown to interfere with the microscopic, electron microscopic and biochemical demonstration of mineral deposition, also inhibit the staining reactions associated in mammalian systems with acid mucopolysaccharides. These observations suggest that, even at the level of an evolving mechanism, sulfur-containing carbohydrates participate in some manner in the deposition of mineral onto a preformed organic matrix.