Jf,nninc;s, Uexki'iU on Physiology of Behavior. 32/ 



the experimentally foimd facts in a convenient way" (25, p. 287). 

 ''The schema of indirect investigation is not a theory at all, but 

 merely a sign language by means of which it is possible to at once 

 express new results in a graphic ('anschaulich') way" (27, p. 31). 

 All emphasis is laid on making the illustration thus "anschaulich" ; 

 that is, of such a character that one can ''see through it" ; see how 

 it would work as a machine works. The author makes extensive 

 use of this "fictitious schema" (25, p. 291), basing long discussions 

 for the greater part of entire papers on its properties. Perhaps 

 nowhere else in biology has a figure of speech, as it were, been 

 worked out in such tremendous detail, through a long series of 

 papers. 



Regarded thus as a figure or illustration, the author appears very 

 successful in constructing apparatus that would produce results simi- 

 lar in their complication and regulatory character to the processes 

 observed in organisms. This has necessarily been done, of course, by 

 attributing new characteristics to the various components wlien 

 required. The tonus is sometimes given the characters of a definite 

 material fluid, and much pains is taken to account for the entire 

 quantity ; again, it ma_y be produced or disappear as required ; some- 

 times it is considered a form of energy; at times it shows the prop- 

 erties of electricity in producing effects by induction (31, p. 195) ; 

 at times we are informed that the figure of a fluid quite fails (25, p. 

 21f3). When the author attempts to show how his complicated 

 machinery may become modified in a way corresponding to the pro- 

 duction of what are called psychologically memory images (31), 

 clearness has to be given up, and the entire figure becomes uncon- 

 vincing. 



As to the value of this figurative and artificial method of pre- 

 senting the results of work, opinions will, of course, differ. The 

 point can be best discussed in connection with a review of the guiding 

 principles and scientific ideals in the author's work ; to this we 

 now turn. It is peculiarly true in the work of v, Uexklill that the 

 author's concrete results cannot be understood without an apprecia- 

 tion of the principles that have guided him. This will lead us to a 

 consideration of his general and theoretical papers. 



