In respect to their functional performance no less than the amount of tissue involved, the muscles are of dominating importance in the body. In the adult they form nearly half the body weight, while their contribution to the metabolism is not less significant. Hence it was that the German physiologist Meyerhof 1 remarked, in a lecture delivered a few months ago in this country:
The problem of the activity of muscle has accompanied physiology, so to speak, from its cradle. This is not astonishing, for the era of physiology coincides with that of technical development. Our science is hardly a hundred years old. In the muscle, nature has produced a machine, so startling and at the same time so perfect, that the explanation of its mechanism could not only give satisfaction to the searching mind, but also promise a rich harvest to the technical progress of mankind. And this problem