FASCICULAR twitching of voluntary muscles has been described in a number of disease entities, such as the atrophic and dystrophic myopathies, and the toxic, metabolic, and infectious affections of the nervous system, as an associated or a related phenomenon. Explanations have been offered in some instances. Attempts to systematize the problem have been actively in progress for over three decades. Recent able summaries of the subject in its related experimental and clinical ramifications have been highlighted by Rosenblueth,1 who cited the voluminous studies of the Cannon laboratories, together with much investigation of his own, which point to a stalemate between the chemical and electrical theories of neurotransmission. The authors cited believe that "presynaptic nerve impulses release acetylcholine when they reach the corresponding post-synaptic elements and that acetylcholine elicits characteristic responses." The excellent survey of McEachern and Rabinovitch2 offers much hope for the more rational attack on clinical disorders