CHAPTER III 



HISTORICAL REVIEW CONCERNING THE ORIGIN AND DEVEL- 

 OPMENT OF IDEAS AND THEORIES REGARDING MOVE- 

 MENTS IN PLANTS AND ANIMALS WITH 

 SPECIAL REFERENCE TO THE QUESTION 

 OF TROPISMS (continued) 



I. The Application of tJie Underlying Principle of Tropisms in 

 the Study of Animal Behavior as opposed to this Study 

 from the Point of View of Comparative Psychology 



Seven years after the appearance of " The Power of 

 Movement In Plants," by Darwin, Loeb began his work on 

 behavior of animals, at Wiirzburg, in an atmosphere per- 

 vaded by the spirit of Sachs. His first paper on the subject, 

 entitled " Die Orientierung der Thiere gegen das Licht 

 (thierischer Heliotropismus)," appeared in January, 1888. 

 A far more important and extensive paper bearing the 

 title " Der Heliotropismus der Thiere und seine Ueberein- 

 stimmung mit dem Heliotropismus der Pflanzen," was 

 brought out in pamphlet form the following year. Other 

 shorter papers followed from time to time. Most of these 

 papers, originally published in German, were translated 

 and published in English in Loeb's " Studies in General 

 Physiology," Chicago, 1905. These translations will be 

 referred to almost exclusively in the following pages. 



Loeb took up the work in animal reactions with the idea 

 of explaining such reactions on chemical and physical 

 bases in opposition to the so-called anthropomorphic 

 explanations current at the time. His object was " to 

 find the agencies which determine unequivocally the direc- 

 tion of motion in animals." He writes (1905, Preface), 

 " I consider a complete knowledge and control of these 

 agencies the biological solution of the metaphysical problem 



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