GENETIC TYPE AND THE ENDOCRINES 619 



for shock was not given. Many efforts were made to develop 

 the avoiding reaction without success. 



As indicated previously, the dogs of group A did not form 

 an adequate conditioned avoiding reaction; when the shock 

 was given the leg was raised and as the shock continued 

 the leg would be raised and lowered alternately. The animals 

 of group B formed a good conditioned avoiding reaction, 

 which appeared without reinforcement, and the whole level 

 of excitability was raised to every signal. The English bull- 

 dog, however, was not disturbed until the signal for the 

 shock was given, that is, the signal had to be more immediate 

 or more closely related to the unconditioned stimulus, than 

 was necessary with other dogs. The bulldog did not antici- 

 pate the shock by the situation, but if the immediate signal 

 was given, a heightened excitatory phase, involving the total 

 postural system, suddenly occurred. When the shock was 

 applied, this animal was also more emotionally disturbed 

 than the animals of groups A and B. It appeared that these 

 dogs are unable to stand painful irritation and to make 

 an adjustment to any situation in which a painful stimulus 

 was used. 



STABLE TYPES PRODUCED BY CROSSING THE ENGLISH BULLDOG 

 WITH THE NORMAL BASSETHOUND 



It has been pointed out above that the English bulldog 

 has many physical abnormalities. The animal also has pe- 

 culiar behavioral reactions, suggesting a mixed behavioral 

 nature. Whether this is the case can be determined by cross 

 breeding the animal with one of the more stable and pre- 

 dictable types, such as the bassethound. By these experiments 

 we not only show the effect of cross breeding a mixed type 

 with one of the more stable types, but also the result obtained 

 when the mixed natures of the bulldog become further modified 

 by bassethound characters among the F2S. 



English bulldog-bassethound F^. These dogs have the 

 short legs, round body, and mild achondroplasia of the basset- 



