564 W. T. JAMES 



been applied when the dog died, and the response at this 

 time was a precise avoiding movement which occurred regu- 

 larly. A negative motor reaction was formed to a second 

 whistle. This dog would not give the conditioned salivary 

 response in any period in which the motor signal was intro- 

 duced, but she did differentiate between the two signals by 

 turning to the food pan when the signal for food was given 

 and by raising the foot when the signal for shock was 

 applied. She was evidently slightly disturbed by the signal 

 for shock, so that the salivary reaction was inhibited. 



With the other dogs classified in this group so many dif- 

 ferent forms of stimuli were not used. The conditioned sali- 

 vary reaction followed the same course, however, in all of 

 them. All members of the group are characterized by the 

 continued appearance of the salivary reaction without onset 

 of inhibition, by a response to the first few negative signals, 

 and by the ability to form a differential reaction after repeti- 

 tion of the signals. They are also characterized by their 

 general alertness, although not greatly disturbed by the signal 

 for shock, or sudden variations within the laboratory. The 

 dogs were not disturbed, for example, if a stranger entered 

 the laboratory during one of the experimental periods. A 

 loud sound introduced for the first time would elicit a vigorous 

 investigatory reaction, but the second and third time it was 

 applied the dog was undisturbed unless it was accompanied 

 either by food or by a shock on the foreleg. The total lab- 

 oratory performance indicates a harmonious relationship 

 between the excitatory and inhibitory processes and reaction 

 systems which make for an adequate and quick adaptability. 



Active type B-minus. If the dogs were studied as indi- 

 viduals and without relation to a large group, the significant 

 differences between those of A-plus and B-minus would not 

 be emphasized. The animals of B-minus are closely related 

 to those of A-plus, yet they have characteristics of the animals 

 of group B. Although alert and active they do not show the 

 extreme restlessness of the latter group. There is less re- 



