REMARKS OF THE TRANSLATOR. 



MANY books on animal psychology, and in par- 

 ticular, on the instinct of animals, have been 

 written within the last quarter of the nineteenth cen- 

 tury. However, the value of these publications is very 

 different. Several authors have deceived themselves 

 and their readers by dropping the chain of argument at 

 the critical point, by evading the difficulty, and using 

 logically unwarrantable, or otherwise obscure phrases. 

 Very few, indeed, are plain and consistent. E. Was- 

 ttiann, well known in Germany as the famous ant biolo- 

 gist, is one of the few. With admirable surety of aim, 

 and well skilled in controversial philosophy, he presses 

 his subject home, sentence by sentence, he is never 

 afraid to face the point at issue, and occasionally ad- 

 duces an appropriate example, mostly taken from his 

 own observation. 



The object of this translation is to make English- 

 speaking scientists acquainted with Wasmann's publi- 

 cations, which are considered in Germany as standard 

 biological literature. The technical terms we have 

 adopted are pretty nearly the same as those of Lubbock, 

 Romanes, etc., in their scientific writings. We took 

 this precaution in order to be better understood by mod- 

 ern scientists. The terms "understanding," "reason" 

 and "intelligence," however, are used for one and the 

 same physical entity. 



In the "American Naturalist" (1901, p. 808), Prof. 



vi 



