14 HARRY MILES JOHNSON 



problem. As a matter of fact, perhaps unconsciously, Roth- 

 mann exposes the weakness of his assumption. He says: "If 

 a wholly disinterested stranger, were introduced for the 

 giving of the food, then it developed that the dogs undertook 

 to get the food at first even without a tone, or at wrong tones, 

 but only in the beginning. As soon as they had accustomed 

 themselves to the change, they did their work correctly." (Ital- 

 ics mine.) Here it is evident that they were not disturbed by 

 fear of the stranger. The simplest explanation is that, missing 

 the first Diener's threatening signs, they reacted at random 

 until they became used to those of the new attendant. 



Rothmann does not report the following facts: (i) The num- 

 ber of animals used; (2) the number of daily trials; (3) the 

 order of presentation of stimuli; (4) the duration of the respec- 

 tive stimuli; (5) the position of the animal with reference to 

 the food when the respective stimuli were given ; and (6) the 

 experimenter's criterion of discrimination. 



The importance of (i) and (2) is self-evident to the experi- 

 mental behaviorist ; that of (3) and (6) has already been pointed 

 out in the comment on Kalischer's work; and Rothmann 's ad- 

 mission of the disturbing effect of (4) on his own work has already 

 been quoted. The importance of (5) — the position of the animal 

 when the stimulus is given, is very great, as it may easily become 

 a basis of reaction. As illustrative of this point, the reader is 

 refeiTed to page 53 of this work for a record of a control test 

 made by the writer. 



Besides training to tones, Rothmann trained some of his 

 animals to come for food at the words "/vowm her,'' and to 

 refrain from coming at the words '' Kopf scher," both combina- 

 tions being sung on the same tone. Reaction to other words of 

 command was also taught. 



The following operative and post-operative procedure was 

 followed: Extirpation of both posterior corpora quadrigemina 

 was performed on four dogs. Three had been previously trained. 

 After the operation, two of these three were trained for about 

 a month to discriminate c-1024 d.v. from the other c's on Roth- 

 mann 's organ, but without success. The fourth animal, pre- 

 viously trained to react only to c-1024 d.v., and which had 

 learned the problem "faultlessly," was again subjected to the 

 training process beginning four weeks after the operation. Three 



