678 



O. D. ANDERSON 



reactive to strong stimulation, such as an electric shock 

 applied to his toe pad. 



Behavior was studied for 2 months while the dog was in 

 this condition. At this point, in order to check the experi- 

 ment and determine definitely that the behavioral effects 

 were due to deficiency in the thyroid secretion, the animal 

 was given thyroid extract subcutaneously, 1 gm. daily for 

 32 days. The salivary C-R tests were continued. The treat- 

 ment produced great improvement in the C-R and in behavior 

 generally (table 11). 



TABLE 11 

 Bog 866<3 



AFTER 

 THYROID- 

 ECTOMY 



Correct responses to positive Met. 120 

 Correct responses to negative Met. 42 



DURING 

 THYROID 

 EXTRACT 



AFTER 



THYROID 



EXTRACT 



WITHDRAWN 



responses to negative Met. 28 

 Average magnitude of C-R to 



Correct 

 .verag 

 positive Met. 120 



85% 

 39% 

 44% 



9% 



100% 



1— 



58% 



100% 



5 



30% 

 100% 



The efficiency of the salivary C-R to the Met. 120 was 

 reduced after the operation (85 per cent to 9 per cent), 

 enhanced during the extract treatments (to 58 per cent) and 

 again reduced when the substance was withdrawn (to 30 per 

 cent). The efficiency of the responses to the negative Met. 

 42 and Met. 28 was at the same time increased (39 per cent 

 to 100 per cent and 44 per cent to 100 per cent, respectively). 

 This increase remained unchanged during the injection of 

 extracts. 



The average magnitude of the C-R was affected. The re- 

 sponse to the Met. 120 was reduced (from 8 to 1-) after 

 thyroidectomy, was enhanced (to 5) during the extract, and 

 was again decreased (to 2) afterward. 



The effect upon the positive C-R may be viewed to best 

 advantage graphically. Plate 108 (figs. 5 and 6) shows graphic 

 records of the effect of the thyroid deficiency on the reflex. 

 Figure 5, taken before the operation, shows a record of head 



