Note 159 — THE MIND OF WOMAN AND THE LOWER RACES

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I have alluded in more than one paper to the theory of tropisms, but this does not imply an acceptance of this theory as stated by Loeb (Der Heliotropismus der Thiere und seine Uebereinstimmung mil dem Heliotropismus der Pflanzen), Vervorn (Das lebendige Substanz), and other representatives of the "mechanical" school of physiologists. The recent researches of Jennings seem to establish the view that reactions of the lower organisms to stimulation are less mechanical than has been assumed by this school. The current theory holds that "the action of the stimulus is directly on the motor organs of that part of the organism upon which the stimulus impinges, thus giving rise to changes in the state of contraction, which produce orientation." Jennings finds that "the responses to stimuli are usually reactions of the organisms as wholes, brought about by some physiological change produced by the stimulus.... The organism reacts as a unit, not as the sum of a number of independently reacting organs." H.S. Jennings, "The Theory of Tropisms," Contributions to the Study of the Behavior of the Lower Organisms (Publications of the Carnegie Institution, 1904), pp. 106, 107.