GENETIC TYPE AND THE ENDOCRINES 627 



salivary gland, and its reaction to the 30 second signal is 

 greater, since more food is consumed. The size of the dog, 

 then, must be considered in the salivary reaction, and for 

 this reason we have emphasized the mode of the performance 

 rather than the value of this reaction alone. The Boston 

 terrier, like the bulldog, was disturbed by the delay of food 

 during the 30 second test signals. During the sounding of 

 the signal the dog would whine, jump up and down, and 

 hold the head over the pan. At times the animal pawed at 

 the disk with its foot. She continued to be highly active 

 throughout the period of training, which extended over a 

 period of more than 2 years. As in the case of the English 

 bulldog, the Boston terrier formed negative reactions and 

 settled down to almost complete inactivity during the interval 

 between the signals. The general mode of performance was 

 the same for both dogs. 



The Boston terrier differed from the English bulldog when 

 the shock and avoiding signal were introduced. The Boston 

 terrier was not disturbed by the signal for shock and behaved 

 similarly to the dogs of group A. This reaction was un- 

 expected, after the experience with the English bulldog and 

 in consideration of the behavior of the animal in the food 

 taking situation. The animal was passive until the shock 

 was applied. The leg movement was slow and deliberate. 

 As the signal and shock continued, the dog made the alternate 

 reactions typical of some of the animals of group A. In 

 contrast to the English bulldog, the Boston terrier also lost 

 the conditioned salivary response after the shock had been 

 applied for a certain length of time. The application of the 

 painful irritation had an inhibiting effect on all reactions, yet 

 the signal for the shock did not elicit the avoiding movement. 



These two dogs of bull type, which are considered pure 

 breeds, do not fit into the behavior groupings of the large 

 majority of the animals. They seem to have characteristics 

 of both group A and B, and also behaviors which are not 

 observed in either group. Their behavior cannot be predicted 

 in the same manner as that of the pure types A and B. 



