Germ-cell origin in the adult caecilian Ichthyophis glutinosus (Linn)

Summary In Ichthyophis glutinosus, no residual spermatogonia traceable to primordial germ cells of the embryo are seen, the primary spermatogonia of each season being formed afresh. Their only source so far as the adult is concerned, is the lining of the collecting duct and its numerous branches which ramify in the testis. No evidences of their origin from the surface epithelial cells of the testis, stromal cells or nurse cells are seen.