GENETIC TYPE AND THE ENDOCRINES 721 



A strong C-R was established in eight trials, which is 

 about the usual rate at which the salivary response is formed 

 in dogs. And the reaction thereafter appeared with undi- 

 minished strength and with a relatively high degree of ef- 

 ficiency. A differentiation was then normally established and 

 maintained. 



When the conditioned reflexes of this dog are compared 

 with those of normal, unoperated dogs, on the basis of ef- 

 ficiency and magnitude, it is at once apparent that her be- 

 havior was quite normal. Table 22 gives the values in dog 

 C-2 as compared with the average values of eight normal 

 dogs, trained in exactly the same way as C-2. 



TABLE 22 

 Dog C^2<? 



AFTKIi REMOVAL, OF AVERAliE VALUES 

 POSTERIOR LOBE i FOR 8 NORMAL, 

 OF PITUITARY DOGS 



Correct responses to positive Met. 120 

 Coircct responses to negative Met. 28 

 Average magnitude of C-R to positive Met. 



120 



87% 85% 



76% 47% 



7 8 



Autopsy on this animal showed that the pars posterior of 

 tlie pituitary had apparently at the time of the operation been 

 " squeezed out" of the surrounding hypophyseal tissue and 

 removed. In addition, a minute portion of the pars anterior, 

 on the left posterior aspect, had been removed. This gave 

 a slightly asymmetrical shape to the pars anterior. Otherwise 

 the tissue appeared normal. 



We may conclude in general that, as in the case of dogs 

 after thyroidectomy and parathyroidectomy, hypophysectomy 

 increases the efficiency of the negative reflex and decreases 

 the efficiency of the positive reflex, all of which is due to a 

 general lowering of excitability. It is reasonable to expect 

 that as general metabolic activity is diminished there would 

 be a concomitant diminution of the functional activities of 

 the central nervous system. 



Such effects as were observed after pituitary removal may 

 well be associated in some way, at present poorly under- 



