An example of the rare biological phenomenon of bacteria living inside the nucleus of a eukaryotic organism, (in this case, the euglenoid flagellate Trachelomonas); the bacteria (green) are encapsulated (as is Rhizobium in leguminous root nodules) but do not fix nitrogen and do not appear to form a symbiotic relationship with the host (they neither aid nor harm the host); the micrograph also shows sections of chromosomes (red) which remain condensed in interphase in euglenoids, nucleoplasm (yellow) and the 2-membraned nuclear envelope. Color enhanced TEM (Transmission Electron Micrograph); magnification: 20,000x.