114 or VITAL MOTION. 



indeed, the heart to pass from diastole into systole, 

 and one of the effects will be the sending of a flood of 

 blood to the sources of innervation. There this flood 

 will excite a free development of nervous influence, 

 which being directed to the heart through the proper 

 channels will induce the state of diastole. In conse- 

 quence of this change the arterial stream is cut off, 

 and the blood sets in to the heart from the auricles 

 and veins. The stoppage of the supply of blood 

 arrests for the moment the free development of nervous 

 energy, and hence one influence is withheld which 

 induced the diastole, and the heart, therefore, returns 

 to the systole. And so we get round the circle. The 

 arterial stream again sets out in consequence of the 

 systole, the blood causes the renewal of nervous 

 energy, the nervous energy induces the diastole, 

 and in this way, the blood being again withheld from 

 the vessels, we arrive at the cause of that suppression 

 of force which occasions the systole. And so, in a 

 regular series, systole will give rise to diastole, and 

 diastole be followed by systole, so long as the vascular 

 and nervous systems retain their integrity. 



No mention is here made of the share which the 

 auricles have in the action of the heart, and it may be 

 thought that this must be directly contradictory to 

 that of which we have been speaking, inasmuch as the 

 diastole of the auricle, and the systole of the ventricle, 

 are cotemporaneous changes, and, vice iiersd^ the sys- 



