correlative transmission and scanning electron microscopy indicated that the spherites ( which are predominantly caco3 ) are formed extracellularly in distinctive bays bounded by secretory-cell processes , and are mobilized anteriorly from the gland lumina to the lumen of a non-secretory pouch , where the majority coalesce and undergo phase transformation to concretions 0.5 - 1.0 mm in diameter consisting of a mass of cuboidal crystals with facets up to 40 micrometers .
C0007634
cell
C1327616
secretory