he biological sciences are dominated by the idea that cells are the functionally autonomous, physically separated, discrete units of life. TThis concept was propounded in the 19th century by discoveries of the cellular structuring of both plants and animals. Moreover, the ap parent autonomy of unicellular eukaryotes, as well as the cellular basis of the mammalian brain (an organ whose anatomy for a long while defied attempts to validate the idea of the cellular nature of its neurons), seemed to provide the final conclusive evidence for the completeness of *cell theory', a theory which has...