400 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



2.58. Tracing No. 12. Contractions of heart irregular. 



3.5. Tracing No. 13. Do., but less than before. Systole and diastole of ventricle both exaggerated. 



3.25. Tracing No. 14. Great increase in systole and diastole both of ventricle and auricles. Long 

 pauses in diastole of ventricle. The curve has fallen below the abscissa-line. 



3.42. Tracing No. 15. Great increase of ventricular diastole, with powerful and complete systolic con- 

 tractions. Rate very slow, only two contractions during two rotations of the drum (two beats 

 during 2 min. 30 sec). 



3.52. Tracing No. 16. Do. Rate still slower, only three contractions of the heart during eight rota- 

 tions of the drum (three beats during 8 min.). Long pauses in extreme ventricular diastole. 



4.2. Tracing No. 17. Do., but systole not so strong. Two contractions of the heart during seven rota- 

 tions of the drum (two beats during 7 min. 48 sec). The contractions are irregular in time and 

 character. 



The cardiograph was now removed from the heart ; the ventricle was seen to be very- 

 large and dark, and it remained motionless for many minutes in this state ; but when 

 the heart was lightly touched, two or three strong and synchronous contractions took 

 place, and then the heart again became motionless with all the chambers, and especially 

 the ventricle, dark and large. 



When again examined, at 5.17, the heart was motionless in the above state for 5 min., 

 when two auricular contractions spontaneously occurred, which were followed by stand- 

 still of the heart in diastole for 9 min., when a single good contraction of the whole heart 

 occurred. After this contraction, the ventricle was not at first so large as it had been 

 before the contraction ; but it gradually became larger and darker, until the condition of 

 extreme diastole was again assumed. 



On the following day, at 11 a.m., the heart was motionless, with the ventricle of 

 medium size and no longer of dark colour. No contraction of any part followed 

 mechanical irritation. The muscle of the ventricle had a neutral reaction, and the skeletal 

 muscles, which were not rigid, had a distinctly alkaline reaction. 



In Experiment LXXXI. there early occurred great increase of the ventricular move- 

 ments, even before the rate of contraction had become slowed, and then a relatively 

 brief period in which ventricular systole predominated over diastole, followed by a period 

 of irregularity in the character of the ventricular contractions during which a bijeminal 

 type was maintained (Plate XV. tracings Nos. 5 and 6). This was succeeded by regularity 

 with much increase of ventricular movement, greater strength of contraction, and slowing 

 due mainly to pauses in ventricular diastole. Ventricular systole again predominated for 

 a short time ; but afterwards, and to the end of the experiment, ventricular diastole pre- 

 dominated, there being, at the same time, powerful and complete contractions of the 

 ventricle and of the auricles, until, after a period in which long pauses occurred in 

 diastole, the heart ceased to contract with all its chambers large and dark. 



While, therefore, the graphic representations of Experiments LXXIX., LXXX., and 

 LXXXI., confirm the observations made in the previous experiments, they also pro- 

 minently display several effects that were not distinctly apparent in them. 



