title: Studies on a macronuclear endosymbiont of Spirostomum ambiguum. II. Ultrastructural comparison of the in situ and the cultivated endosymbiont.
mesh_terms: D001419:Bacteria / Q000648:ultrastructure*; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000382:microbiology; D016798:Ciliophora / Q000382:microbiology*; D013559:Symbiosis