148 LECTURE VI. 



like the heart, originated a kind of rhythmical pulsating 

 movement, which was capable of directly furthering the 

 onward movement of the blood, so that an arterial hyper- 

 semia would be the result of an increased pulsation in 

 the vessels. 



We are indeed acquainted with one isolated fact which 

 is a proof that a real rhythmical movement does take 

 place in the arterial walls ; and this was first observed 

 by Schiff in the ears of rabbits. Its rhythm, however, 

 does not at all correspond woth that of the well-known 

 arterial pulsation ; the only counterpart to it exists in 

 the movements which had previously been observed by 

 Wharton Jones in the veins of the wings of bats, and 

 proceed in an extremely slow and quiet manner. I have 

 studied these phenomena in bats, and convinced myself 

 that the rhythm coincindes neither with the cardiac nor 

 the respiratory movements ; it is quite a peculiar, but 

 comparatively not very forcible, movement, and takes 

 place .after tolerably long pauses, longer ones than are 

 observed in the case of the circulation and shorter than 

 those which occur in respiration. In the ears of rabbits, 

 also, the contractions of the arteries are far slower than 

 the cardiac and respiratory movements. 



After excluding these phenomena, which manifestly 

 ought not to be explained in such a way as to support 

 the old view of the local occurrence of pulsation, the 

 essential fact remains, that the muscular fibres of a ves- 

 sel contract upon the application of every stimulus which 

 sets them in action, but that this contraction is not pro- 

 pagated in a peristaltic manner, but is confined to the 

 spot irritated, or, at most, extends a little beyond, and 

 continues for a certain length of time at this spot. The 

 more muscular the vessel is, the more lasting and forcible 

 is the contraction and the greater is the obstruction 

 experienced by the current of blood. The smaller the 



