THE INNERVATION OP THE HEART. 



447 



tary body, which becomes itself activated, under these circum- 

 stances, through the carotid plexus. The- vagus is not alone 

 stimulated, therefore, but the suprarenal glands likewise: pre- 

 cisely the most effective means to bring about the effects 

 witnessed, as we view the process. This is affirmed by the fol- 

 lowing remarks by the same author: "Last, the contrast is 



Cr. 



IX 



-A.8b. 



S.KC, 



DIAGRAMMATIC REPRESENTATION OF THE COURSE OF CARDIAC 



AUGMENTOR FIBERS IN THE FROG. (Foster.) 



completed by the fact that the augmentation resulting from 

 the stimulation of the sympathetic is followed by a period of 

 reaction in which the beats are feebler; in other words, aug- 

 mentation is followed by exhaustion; and, indeed, by repeated 

 stimulation of these sympathetic fibers, a fairly vigorous blood- 

 less heart may be reduced to a very feeble condition." 



