PLATE 1 



EXPLANATION OF FIGURES 



Fig. 1 The effect of increased respiratory movements upon vasomotor re- 

 flexes. Bitch. 9 kilos. 10/5/1918. Ether. The left sciatic nerve was stimu- 

 lated at intervals, the stimulus increasing from left to right. Upper curve, 

 respiratory movements. Lower curve, blood-pressure. Base line is that of 

 zero pressure, with periods of stimulation. The height of the blood-pressure 

 in mm. Hg. is indicated by the cm. measured out and numbered. Time in sec- 

 onds. For further explanation see text. 



Fig. 2 Increased respiratory movements prevented by very deep narcosis. 

 Same bitch as in figure 1. For explanation see text. 



Fig. 3 Effect of increased respiratory movements upon blood-pressure. 

 Bitch. 14 kilos. 30/5/1918. Ether. 'Thorax intact. The left sciatic nerve 

 was stimulated. The result is a marked fall of blood-pressure. 



Fig. 4 Effect of increased respiratory movements upon blood-pressure pre- 

 vented by opening the thorax. Same bitch as in figure 3. Thorax wide open in 

 the middle line. The same nerve was stimulated with the same strength of 

 stimulus as in figure 3. The result is a marked rise of blood-pressure. 



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