HABIT FORMATION IN" THE DOG 7 



of my animals, after making three or four wrong choices succes- 

 sively have finished a series of fifteen trials correctly. 



To return to Kalischer's procedure: He says, "From the 

 fifth or sixth day on, even if I held the bit of meat in the open 

 hand, many animals would no longer attempt to seize it at the 

 'Gegentone.' Thus ever more frequently correct reactions en- 

 sued." From this point on the animals were "punished by a 

 light blow on the jaw when they snapped falsely after the food." 



Some of the animals were taught to take food at high tones 

 — :ome at c-2048 d.v. — ^and others at as low tones as "07."*^ 

 The "Gegentone" chosen at first were those lying as far as 

 possible from the food-tone. After the animals had learned to 

 inhibit reaction to these, others nearer the food-tone were chosen. 

 Kalischer says that the greater the difference between food-tone 

 and "Gegenton" the more quicldy the animal learned to dis- 

 criminate ; but that it was possible and not very difficult to 

 train the animal to discriminate between the food-tone and one 

 only a semi-tone removed. We should examine with some care 

 his description of the animals' behavior in the experimental 

 situation, however. " Bei den w^eitab vom Fresston liegenden 

 Tonen pflegte spater der gut dressierte Hund, scheinbar er- 

 schreckt, schnell zuriickzuspringen, wahrend er bei den naher 

 leigenden Gegentonen offer Neigung zeigte, zuzuschnappen, (italics 

 mine) was sich deutlich an den Kopfbew^egungen beobachten 

 Hess." Again: "Liess man den Fresston oft hintereinander 

 ertonen, die zunachst prompt nach die Fleischstticken gegriffen 

 hatten, Ermtidungserscheinen geltend." "Die Tiere 

 horten auf , nach den Fleischstucken zu greifen ; und erst wenn 

 man zwischendurch wieder einen der Gegentone angeschlagen 

 hatte, griff'en die Tiere von neuem beim Fresston wieder in 

 gewohnter Weise zu. * * * Auch hier war es von Zeit zu 

 Zeit notig, zwischendurch einen der Gegentonen erklingen zu 

 lassen." 



These remarks indicate that Kalischer regarded his animals 

 as discriminating even thougn they sometimes did not react to 

 the food-tone and did not inhibit reaction to "Gegentone." 

 We may then seriously inquire what was the experimenter's 

 criterion of discrimination. How could he know that failure 

 to respond was due to fatigue and is not rather evidence of lack 



^^ This is doubtless a misprint: Ci, 64 d.v., is probably meant. 



