In biology, particularly cell biology, the term organelle is used to describe any one of a number of types of subcellular structures, historically identified through the use of some form of microscopy.
A few large organelles probably originated from endosymbiont bacteria:
... but Tolstoy clashed with the editor, Mikhail Katkov, over issues that arose in the final installment. Consequently, the novel's first complete appearance was in book ...