On Electrical Stimulation of tlie Frogs Heart, 489 1 



Thus the induced auricular contraction in tins instance, instead of 

 passing a motor impulse downwards to the ventricle, appears not 

 only to check the reduplication, but greatly to prolong the 

 diastole. 



It is easily recognised from the auricular tracing that the induced 

 contraction is one of the unfilled cavities (fig. S), but though little 

 or no blood passes into the ventricle, a positive effect upon the latter 

 is still produced. 



