GENETIC TYPE AND THE ENDOCRINES 599 



active or B group. These breeds are also widely different 

 in physical form. 



The bassethound has an extreme degree of achondroplasia 

 in the legs and disproportionately large feet, with toes tend- 

 ing to spread apart. No other region of the body, however, 

 shows any noticeable trace of achondroplasia. The head is 

 long and well developed, and characterized by long, drooping 

 ears. The chest is rounded, and the abdomen full, and since 

 there is a tendency to obesity, these animals present a stocky 

 appearance. 



In contrast to the bassethound, the German shepherd and 

 Saluki have long, thin, straight legs. Like the bassethound, 

 the head is long. The body is more thin and saggital shaped 

 than round, and since as a rule the abdomen is not equally 

 as deep as the chest, they have a thin "streamlined" appear- 

 ance. The greatest depth of the arrow shaped chest occurs 

 in the region of the seventh or eighth rib. 



These two types of pure breeds differ so widely in physique 

 and behavior as to suggest a possible relationship between 

 morphological form and neurophysiological characteristics. 

 This would mean that the animals inherited not only a definite 

 physical form, but also a particular interorganismal structure, 

 including nervous and glandular processes, which determine 

 their modes of reaction. If such were the case, the question may 

 be raised, whether the factors determining physical form and 

 behavior may be dissociated, or whether a definite behavior 

 nature would always occur with a certain form. Another 

 question is whether the factors have a natural interdependence 

 or have become linked by selective breeding. Further, why 

 is there so little variation in the behavior of the members 

 of each of these breeds while great variation is presented 

 among other dogs! One approach to an answer for these 

 questions would be a comparison of the behaviors and physical 

 form of the first and second generation hybrids obtained by 

 cross breeding the extreme types. 



If the dogs are to be studied with reference to physical 

 characteristics as well as behavior, some method of contrast- 



