CONTENTS 



Contents: Introductory. Earliest period. Francis Glisson as founder 

 of the doctrine of irritability. Albrccht von Haller. The vitalists. 

 Bordeii and Barthcz. John Brown's system. Johannes Muller 

 and the specific energy of living substance. Rudolf Virchoufs 

 doctrine of the irritability of the cell. Discovery of the inhibitory 

 effects of stimulation. Weber, Schiff, Goltz, Setschenow, Sher- 

 rington. Claude Bernard studies on narcosis. Tropisms. Ehren- 

 berg, Engelmann, Pfcffer, Strassburger, Stahl. Semon's specu- 

 lations on mneme. 



II 



Contents: Principles of scientific knowledge and research. Origin 

 and meaning of the conception of cause. Cause and condition. 

 Criticism of the conception of cause. The conditional point of 

 view. Conception of cause. The conditional point of view applied 

 to the investigation of life. Conception of vital conditions. Defi- 

 nition of the conception of stimulation 18 



III 



Contents: The quality of the stimulus. Positive and negative altera- 

 tions of the factors which act as vital conditions. Extent of the 

 alteration in vital conditions or intensity of the stimulus. Thresh- 

 old stimuli, sub-threshold, submaximal, maximal and supermaxi- 

 mal intensities of stimulus. Relations between the intensity of 

 stimulus and the amount of response. The Weber and Fechner 

 law. All or none law. Time relations of the course of the 

 stimulus. Form of individual stimulus. Absolute and relative 

 rapidity in the course of the stimulus. Duration of the stimulus 

 after reaching its highest point. Adaptation to persistent stimuli. 

 Series of individual stimuli. Rhythmical stimuli. The Nernst 

 law. 39 



