Color enhanced TEM of Intranuclear bacteria. An example of the rare biological phenomenon of bacteria living inside the nucleous 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.