This book, to say the least, is provocative of thought, and that is saying a good deal. It is obviously an elaboration of ideas which the author has held in less complete form for many years and which are now backed up by the results of many researches by himself and many others.

In the main the author conceives of the human organism as an energy system and of the organs as parts of such system rather than as discrete entities of the older physiologists. The nature of the energy that streams from place to place as it seeks equilibrium is conceived of as being electrical. The various pathways are the conductors and the various cell membranes and synapses are devices for preventing the constant flow which would result in exhaustion by impounding the accumulating energy like dams. He traces the human organism all the way from its monocellular origin to its present estate and sees in the distinction between nucleus and cytoplasm a fundamental type of arrangement which has followed through in the patterns of the higher animals. The nucleus