GENETIC TYPE AND THE ENDOCRINES 625 



THE SIGNIFICANCE OF SIZE AND ITS RELATION TO 

 BEHAVIORAL TYPE 



The question may be raised, whether the inactive nature 

 exemplified by the bassethound, and the highly active nature 

 as found in the German shepherd, occur in other breeds which 

 differ in size and general appearance. In other words, does 

 the behavioral nature, as isolated in the above experiments, 

 bear any direct relation to the size of the animal, or is the 

 significant factor the organization or patterning of the genetic 

 factors? In order to answer this question, some of the 

 smaller animals were studied in the same experimental situa- 

 tions discussed for the above breeds. There are other hound 

 types, similar in general bodily form to the bassethound, 

 which differ in size, as for example the dachshund, beagle 

 hound, and bloodhound. Another bulldog type is the American 

 bred Boston terrier which is smaller than the English bulldog 

 but which has similar physical abnormalities. These animals 

 differing in size yet with the same general morphological 

 characteristics as those animals already discussed were not 

 extensively studied. The dachshund, which shows many char- 

 acteristics of the bassethound, was the first small dog to be 

 considered. 



Dachshund. The dachshund has a normal head, body and 

 tail, resembling these characters in the bassethound; it also 

 has pronounced achondroplasia in the much shortened ex- 

 tremities. Although these two animals are comparable in 

 physical form, the dachshund is somewhat dwarfed, reaching 

 only about half the size of the bassethound. The dachshund 

 also tends to be round bodied, although it is not as extreme 

 in this character as the bassethound. 



Since no pure dachshunds were available for these experi- 

 ments, two dogs which were predominantly dachshund in 

 inheritance were trained. One of these, 336 9 , with a chest 

 index of 76, was a hybrid obtained by crossing a pure dachs- 

 hund with a dachshund-Brussels griffon F x . The other animal, 

 248 9 , also with a chest index of 76, was obtained from a 

 mating between a dachshund and a dachshund-Boston terrier 



