title: Cell lineage in development.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004625:Embryo, Nonmammalian / Q000648:ultrastructure; D004627:Embryonic Induction; D005314:Embryonic and Fetal Development; D007865:Leeches / Q000196:embryology / Q000648:ultrastructure; D009024:Morphogenesis