THE ROLE OF THE GLANDS OF INTERNAL SECRE- 

 TION IN THE PRODUCTION OF BEHAVIORAL 

 TYPES IN THE DOG 



BASED ON A STUDY OF BEHAVIOR BY THE CONDITIONED REFLEX 

 METHOD 



THE PROBLEM 



The present section deals witli the influence of the internal 

 secretions upon reflex action and behavior in the dog. 



The author wishes to extend his thanks to Professor C. R. 

 Stockard for supplying- the valuable animals of known pedi- 

 gree and morphologic type, since only with such material 

 could these studies be fully dependable; for the benefit of 

 his advice in planning and arranging the experiments; and 

 for his constructive criticism and valuable suggestions during 

 the progress of the work. The author wishes also to thank 

 Professor Joshua Sweet, who not only performed all the 

 more difficult surgical operations in this work, but who also 

 gave freely of his time in discussions of the clinical and 

 experimental significance of disturbances of the internal secre- 

 tions. 



The behavior of various dog breeds has been the subject of 

 special investigation both at the Cornell Anatomy Farm and 

 in the Department of Anatomy in New York City. James 

 ( '34) has made an extensive study of the conditioned reflexes 

 in different pure breeds and their hybrids. And Anderson 

 and James have studied the neuromuscular activity of the 

 different morphological types employed in the general studies 

 discussed in the foregoing chapters. Notable behavioral varia- 

 tions are found among the different breeds, and it has been 

 demonstrated that these are associated with the breed dif- 

 ferences. The mode of behavior thus depends in large part 

 upon the influence of inherited constitutional factors as- 



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