title: Fine structure of fusion reaction in compound ascidian Botryllus primigenus OKA.
mesh_terms: D000818:Animals; D004848:Epithelium / Q000648:ultrastructure; D007365:Intercellular Junctions / Q000648:ultrastructure; D008854:Microscopy, Electron; D014561:Urochordata / Q000502:physiology* / Q000648:ultrastructure