GENETIC TYPE AND THE ENDOCRINES 623 



specific parts. Other relatively simple associations could not 

 be formed. Their behavior seemed to be limited within the 

 range of the kennel, and when removed from this environ- 

 ment they became highly disturbed. 



Summary. The English bulldog has many physical ab- 

 normalities and behavioral tendencies not shown by the basset- 

 hound and German shepherd or the hybrids obtained by 

 cross breeding these two dogs. The bulldog has some be- 

 havioral characteristics of both the bassethound and shep- 

 herd, yet in many situations is completely different from 

 both. By mating the bulldog with the more normal basset- 

 hound, relatively normal hybrids are produced. The F x s 

 fall into the inactive group in behavior, but are more ex- 

 citable than the pure bassethound. Among the F 2 s, there is 

 a wider variety of physical form as well as behavioral char- 

 acteristics than is found for the bassethound-shepherd F 2 s. 

 This indicates that the parent bulldog is more mixed genetical- 

 ly than either the shepherd or the bassethound. The F 2 s 

 resembling the bassethound in appearance fall into the in- 

 hibited group in the salivary experiments, but none could 

 be trained in the motor situation. The intense emotional 

 nature shown in situations involving pain and danger is 

 probably dependent on many factors, but since the bulldog- 

 has behavioral characteristics similar to the bassethound, 

 these, together with the characteristics from the parent bas- 

 sethound, dominate in the F^. Among the F 2 s, however, 

 in which the factors become separated, those determining 

 this intense emotional nature are predominant. If a larger 

 number of F 2 s were trained, possibly some would be found 

 which would behave like the bassethound in the motor experi- 

 ments. The purposes of the present experiment had been 

 completed, however, inasmuch as it was shown that where 

 there is a greater variety in physical form and glandular 

 conditions, there is also a greater variation in behavioral 

 natures, and in this connection there was no need to train 

 a larger number of animals. 



