Lamellar bodies in differentiating insect tissues during basal lamina formation as revealed by tannic acid

Tannic acid penetrates differentiating tissues differentially resulting in variable contrast, extraction and dense bodies with a lamellar substructure. The penetrability appears to correlate with the existence and/or robustness of a basal lamina. In the male genital tract, probably of mesodermal origin, tannic acid penetrates the epithelium until there is a basal lamina, but in the ectodermal bursa copulatrix it does not penetrate since there is always a basal lamina. The lamellae of the dense bodies have a center-to-center spacing of 4.65 +/- 0.025 nm, dimensions which resemble those of phospholipids.