707 



thormone, the decline during the continued administration 

 of the substance, and the weak state in the period after 

 withdrawal of the extract, followed by disappearance in the 

 terminal period. 



During the 4 months in which the dog was studied after 

 operation, general behavior outside the laboratory was also 



EFFECT OF THYRO-P/mTHYROIDeCTOflY 

 OF THE SUBSEQUENT ADMINI5T7VITION OF PARATHYROID EXTRACT 

 ON THE CONDITIONED MOTOR REFLEX 



#856 



v gf l Ulifc 



ettrtcf en fflrmf* Jtfi 



Thy r o-faarathyro i dect omized 



Text-figure 125. A chart showing effect of thyro-parathyroidectomy and of 

 the subsequent administration of parathyroid extract on the conditioned motor 

 reflex in dog 856. Note diminution of the conditioned reflex after the operation 

 and the slight enhancing effect of the extract. The value of the reflex is reduced 

 to zero in the fourth month after the operation. 



affected. The limbs were stiff, and movements were poorly 

 coordinated in walking. The gait was peculiar, the body 

 swaying from side to side, and the course being on a zig-zag 

 line. Each step was jumpy. Occasional twitching of the 

 temporal muscles was observed. The animal slept a great 

 deal and was very unresponsive to various natural stimula- 

 tions in the kennel. It is also interesting to note that on no 



