GENETIC TYPE AND THE ENDOCRINES 673 



she stood trembling 1 in a corner. A sudden scraping of the 

 foot on the floor almost always startled this animal. 



The C-R in this dog was formed easily in sixteen trials. 

 The reaction, though weak, was considered normal during 

 a period of 9 months. During this time the formation of a 

 discrimination between Met. 120 and Met. 42 was attempted. 

 The animal failed almost completely in this. After repeated 

 attempts during 3 months to force her to discriminate be- 

 tween the two rates, the general behavior gradually became 

 abnormal. The C-R slowly diminished in magnitude until 

 finally, at almost every trial, no flow of saliva was evoked 

 by the Met. 120. This dog previously had stood quite still 

 during the intervals between stimuli but now moved restlessly 

 about and constantly attempted to back off the experimental 

 platform. The head was moved about in alert poses. The 

 restlessness almost always became much more pronounced 

 the moment the negative Met. 42 was started. All the slight 

 signs of nervousness and shyness noted earlier now became 

 greatly exaggerated until she was almost unmanageable. At 

 this point we concluded that all the typical signs of the ex- 

 perimental neurosis as in Pavlov's classical experiments ( '27) 

 were evident. Realizing that symptoms of this disturbance 

 in the dog often manifest themselves coincidently with the 

 continued presentation of a problem too difficult for the 

 animal to solve, an easier problem was presented. The Met. 

 42 was changed to Met. 28. Although some discrimination 

 was evident with this slower metronome, the animal still 

 remained as disturbed as before. 



The C-R in this bitch, although entirely absent most of the 

 time after the "experimental neurosis," did appear with 

 considerable frequency and strength every time she came 

 into heat (see plate 108 and text-figure 115). As pointed out 

 earlier, there appears to be an association between the re- 

 appearance of the C-R and the heightened glandular activity 

 presumably occurring during the oestrus. This animal pro- 

 vided a means of testing one aspect of this question, namely, 

 whether it would be possible to cause a reappearance of the 



