GENETIC TYPE AND THE ENDOCRINES 613 



vigorous conditioned salivary reactions. Among these four 

 dogs there were no significant differences in behavior; all 

 were classified as A-plus. However, one animal of this litter, 

 1301$, was unable to make an adjustment to the laboratory 

 and thus was classed with the extremely timid and inhibited 

 group which was disturbed by every variation in the environ- 

 ment. She was discussed in detail in the section on abnormal 

 types. Although this group of dogs is predominantly basset- 

 hound in inheritance, there is some variation in bodily form 

 and also variations in behavior. The breeding together of 

 two backcrossed FjS on the bassethound, therefore, does not 

 produce a homozygous type. The extremely timid behavior 

 of 1301 9 would seem to be due to a highly mixed nature, 

 since this peculiar reaction does not appear in the grand- 

 parents. 



General summary of the bassethound and shepherd crosses. 

 In the two polar types, A and B, there seems to be a definite 

 correlation between bodily form and behavior. There is a 

 harmonious relationship among the genetic factors for physi- 

 cal form, glandular conditions and behavior. When the two 

 polar types are bred together, however, this relationship 

 breaks up. There is more variation in behavior among the 

 F 2 s than among the FjS. A dog may inherit the bodily form 

 of the bassethound, yet behave like the excitable shepherd 

 dog under experimental conditions. Others seem to have 

 some characteristic physical qualities of each parent and 

 the behavior qualities of both polar types. These are con- 

 sidered animals with mixed behavior patterns. 



Consideration of the backcrossed bassethound-German 

 shepherd Fj on the bassethound, and offspring from two 

 backcrossed animals, shows that among hybrids there may 

 be great resemblance in bodily form yet a wide divergence 

 in behavior. Once the physical form and behavior qualities 

 of two pure types are mixed, it requires many selective 

 breedings to isolate the two features again. 



