EXPLANATION OF PLATES XCVIII. TO 01. 



Fir,. 229. Trucing drawn by a lever applied directly to the apex of the heart of the frog. 



Fie. 234. Tracing of endocardial pressure of heart of frog, obtained by Coats' method. 



Fins. 238(1 and b. Synchronous tracings of arterial pressure, and respiratory movement of air in trachea, 

 tJikitn () immediately before, and (b) one minute after, section of both vagi. The lever kymograph (flg. 257) 

 was employed. Arterial pressure before section about 150 in.m., after section about 180 m.m. Pulse rate 

 )efore section no, after section 260. Respirations before section 24, after section 10. The characteristic violence 

 of the expiratory movements after section is well shown. 



FICI. 239. (i. Tracing of arterial pressure of 'rabbit, obtained with Pick's kymograph (fig. 205) during 

 excitation of peripheral end of divided vagus, with feeble induced currents (secondary coil far removed 

 from primary). Duration of excitation of nerve indicated by asterisks, b. The same, with secoiidary coil 

 brought nearer. 



FIG. 245. Tracing of arterial pressure with Pick's kymograph during excitation of the central end of the 

 depressor nerve ( 82). 



FIG. 232. a. Tracing obtained with the cardiograph, when the button is applied to the seat of impulse of 

 the human heart, b. Tracing obtained when the button is applied either outside of the impulse or nearer the 

 sternum. The line of sudden descent in b coincides with that of sudden ascent in a. Both are coincident 

 with the sudden hardening of the ventricle, i.e., with the complete closure of the mitral and tricuspid 

 valves ( 60). 



FIG. 246 bis. Tracing of respiration of frog ( 86). 



FIG. 249. Tracing of iutrathoracic pressure ( 90). 



FIO. 248. Tracing obtained with the stethometer when applied as in flg. 247. i. Inspiration ; e, expiration. 

 Immediately after a, a notch in each of the curves occurs, the descending limb of which expresses the 

 moment of cardiac impulse. Compare fig. 2326 ( 89). 



FIG. 253. Respiration of the cat before and after section of both vagi. The tracing expresses the variations 

 of pressure which occur in the air passages during each respiratory act. In b the horizontal line is that 

 drawn by the lever when at rest ; consequently, when the pressure in the air passages is less than that of 

 the atmosphere the lever rises, when it is greater it falls. The sudden expiratory movement which is the 

 most, marked characteristic of the mode of breathing after section of both nerves commences at e ( 92). 



FIG. 263(1. Tracing of arterial pressure and respiratory movements in the second stage of asphyxia by occlusion. 

 a p, Arterial pressure ; i, respiration. Both tracings express the movements of mercurial manometers ft 109). 



FIG. 2636. Slow asphyxia. The lower tracing expresses the movements of an elastic bag in communication 

 with the trachea (| no). 



FIGS. 259-261. Tracings of respiratory movements of the dog before and after curarization ( 105), 



FIG. 262. Tracings of artificial respiration aid arterial pressure, showing Traube's curves, as seen with vagi 

 intact ( 106). 



FIG. 264. Effect of a single injection of air in a curarized dog, after long discontinuance of artificial respiration 

 (i in). 



FIGS. 2*4 and 255. Excitation of the central end of the vagus in the rabbit ( ICG and 103). 



FIG. 256. Excitation of the central end of the superior larynge.il nerve ( 194). 



