GENETIC TYPE AND THE ENDOCEINES 603 



Since the bassethound and German shepherd differ so widely 

 in behavior, and are entirely opposite in physical form, hy- 

 brids derived from crossing these two pure bred animals 

 were analyzed to see how modification of the physical form 

 by crossbreeding affected the behavior. 



The criterion of the behavioral classifications has been 

 treated fully in the previous sections, and the discussion to 

 follow will be confined to a designation of the behavioral type 

 of each animal and its relationship to physical form. As has 

 already been pointed out, the bassethound falls into group 

 A, or the inactive and inhibited group, under each experi- 

 mental condition. The German shepherd, on the other hand, 

 is highly active and excitable, and properly fits into group B. 

 In any behavioral situation in which these two opposite types 

 are studied, the contrast between them is marked. In the 

 conditioned food taking situation, the reactions of the basset- 

 hound become sluggish, and the conditioned reactions are 

 gradually inhibited; in the conditioned motor situation this 

 animal again performs in a sluggish, irregular manner and 

 tends to respond to the unconditioned signal rather than 

 the conditioning one. The German shepherd, on the other 

 hand, remains highly active and responsive in the conditioned 

 food taking situation, giving vigorous conditioned salivary 

 reactions, with short delays in the responses and without 

 showing any tendency to develop complete inhibition. This 

 animal forms positive responses to all signals with little 

 difficulty, but has some difficulty in developing negative re- 

 actions. In the motor situations, the German shepherd is 

 again highly responsive, somewhat disturbed, alert, tense, 

 quick acting, and always careful to make the avoiding move- 

 ment. The reactions of both the bassethound and the German 

 shepherd are predictable in any situation in which they are 

 studied the bassethound will be among the inhibited dogs 

 and the shepherd among the excitable. 



Bassethound-German shepherd F^s. Theoretically, the ge- 

 netics of the animals obtained by crossing the bassethound 

 and the German shepherd is relatively simple. Each F t 

 should inherit the same factors from both parents, and for 



