THE REACTIONS OF ORGANISMS TO LIGHT 217 



Protisten Studien" covering 218 pages. In this he describes in 

 detail the reactions of a number of animals and discusses them 

 from a physico-chemical point of view. In the preface it is 

 stated that he began the work in 1886 just as I stated in my 

 account. 



Loeb's first paper dealing with behavior appeared in 1888, 

 under the title " Die Orientieung der Thiere gegen das Light. 

 (Thierischer Heliotropismus)." It is a sort of preliminary 

 report consisting of but five pages published in the proceedings 

 of a medical society at Wurzburg. A much longer paper with 

 a similar title appeared later in pamphlet form. This pamph- 

 let is dated 1890 indicating that it was published during the 

 year following the date of publication of Verworn's paper. Loeb, 

 however, usually gives the date 1889 in referring to this paper 

 (see Studies in General Physiology and Dynamics of Living 

 Matter) thus intimating that it was not preceded by Verworn's 

 paper. Why he gives an earlier date than that found on the 

 pamphlet I am unable to say. 



These are all of the important facts at my command concern- 

 ing the dates of the earlier works of these authors. Those 

 interested in the question of priority may use them as they see 

 fit in drawing their conclusions. However in discussing priority 

 of work on the behavior of organisms from the mechanical point 

 of view the brilliant investigations of Engelmann beginning as 

 early as 1869 must not be overlooked. 



