ILLUSTRATIONS 



Plate I 



Fig. 1. Intrapulmonic pressure during apomorphine emesis with the trach- 

 eal cannula closed. C indicates closure of the third limb of 

 the Y-tube; 1-5, deep inspirations at the beginning of vomiting; 

 6-7, expulsion time; O, opening of the third limb of the Y-tube; 

 Z, zero line. 

 2. Pressure produced by the water-air pump when the dog vomits. 

 1, beginning of vomiting; 2, end of vomiting; >F-W, waves due 

 to swallowing of vomitus ; w, waves due to oscillations of mercury 

 in seeking its normal level; z, zero line. 



Plate II 



Fig. 1. Pressure produced by the water-air pump when the escape of air 

 through the glottis is artificially prevented. 1, occlusion was 

 produced between the tracheal cannula and Y-tube; 2, occlusion 

 removed; w, waves due to oscillations of mercury in seeking its 

 normal level; z, zero line. 

 2. Intrapulmonic pressure during apomorphine emesis with the trachea 

 not occluded. 1-8 indicate deep inspirations at the beginning 

 of vomiting; 9, beginning of contraction of abdominal wall; v, 

 appearance of vomitus in the mouth. 



TEXT FIGURE 



Fig. 1. Shows the connection of the glottis to b, the mercury manometer, 

 and to a, the water-air-pressure pump. 



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