555 



to contraction by direct stimulation, and registered it by means of 

 a stationary drum covered by smoked paper. Tiien I substituted 

 waler for the fluid of Ringer. After 5 minutes the point of the 

 lever had already distinctly risen, then the drum is turned round a 

 little way, and by direct stimulation another contraction is brought 

 about and registered. In this way the drum is turned a little way b}^ 

 the hand every live minutes, and afterwards a contraction is registered on 



the stationary drum. The result is reproduced 

 in Fig. 1. We see that after every five minutes 

 the point of the lever has I'isen, and that 

 after 25 minutes the point of the lever has 

 mounted over the top of the first registered 

 curve. Then on a stimulation the muscle 

 no longer i-eacts with an abbreviation. This 

 experiment can be explained as follows : 

 F^g- ^- Because the muscle has been so long sub- 



merged in water, it becomes saturated with water, swells and assumes 

 rather a globular foi'm. This causes the ends of the muscle to come 

 nearer to each other, and an inflation-abbreviation is the consequence. 

 As soon as this inflation-abbreviation surpasses the height of the 

 "Zucking", the mechanical proportions have assumed such a character 

 that an abbreviation can no more become manifest after a stimulation. 

 The irritability and conductivity are intact, and the abbreviation 

 exists already on account of the inflation. The active abbreviation 

 of the fibrils no more approaches the ends of the muscle nearer 

 to each other, because the inflation has already appi^oached them at 

 the smallest possible distance. What is decisive in this respect is 

 the fact, that such a swollen muscle can no more dilate. 



I arranged my experiments on the frog's heart in the following 

 manner. I fastened a canula of Kronecker through the sinus venosus 

 in the auricles, after I had destroyed the septum atriorum and the 

 atrioventriculary-valves. Then I imbibed the heart with the solu- 

 tion of Ringer under the pressure of a column of water 9 mm., 

 and registered the heart-curves by means of suspension on a drum 

 covered by smoked paper. Then I substituted by water the fluid of 

 Ringer. Within a short time the heart stood still and indeed at a 

 level with the tops of the formerly registered curves (vide Fig. 2). 

 If thereupon the heart is again imbibed with the fluid of Ringer, 

 we can make the heart pulsate again, after the inflation-abbreviation 

 of the heart-muscle has first diminished. The heart has, like the 

 skeleton-muscles, sustained a rather important inflation by the im- 

 bibition with water, and the distance from the basis to the point of the 



