GENETIC TYPE AND THE ENDOCRINES 



671 



Text-figure 119. (1) Kymographic record showing the motor reactions of 

 dog 868 in the period prior to the administration of thyroid extract. Note the 

 conditioned leg reaction (fourth line from top) to the Met. 120 and shock and 

 the lack of reaction to the Met. 36 (negative). Note that the animal stands 

 quietly in the interval between the two stimuli. (2) Graphic record showing 

 the reactions of dog 868 during the administration of thyroid extract. Contrast 

 the exaggerated motor reactions with those shown in figure 1. Here the reaction 

 is evoked not only by Met. 120 but also by the negative Met. 36. Notice also 

 that the animal constantly moves the right foreleg in small, jerky movements. 

 The movement of the head and irregularity in respiration, together with these 

 spontaneous leg movements, suggest the picture of the highly nervous or neurotic 

 animal. 



