98 PULSE RECORDS IN THEIR RELATION TO 



auricle, and reported that the ring is not completely closed in 

 ventricular systole, for the multiple dome of the tricuspid valves 

 is palpable at this phase. 1 It must be remembered that such an 

 experiment is conducted with the thorax open, and also that 

 the palpating finger is frequently misled in attempting to gauge 

 changes of volume where there are also changes of pressure. In a 

 consideration of the possibility of this bulging the experiments of 

 Roy and Adami are of importance. These observers recorded the 

 contractions of the papillary muscles by means of a hook passed 

 through the wall of the auricle and around a chorda ; they 

 registered, simultaneously, the movements of the heart wall itself. 

 The conclusion arrived at was that there is an appreciable delay 

 between the onset of ventricular wall and papillary muscle con- 

 traction. Now this conclusion has been called in question by 

 Haycraft and Paterson. In the freshly excised heart they found 

 the contraction of the papillary muscles and adjoining part of the 

 ventricular wall to be synchronous. The subject has recently 

 received further attention from Saltzman ( 44 ), who experimented 

 on the perfused heart. His findings, though they lack complete 

 uniformity, on the whole favour the view that the musculature 

 of the heart contracts according to the length of the branches of 

 the Purkinje system which supply the particular part considered. 

 The order of contraction in his typical experiments is as follows : 

 First, the base of the heart ; secondly, the papillary muscles and 

 adjoining wall ; and thirdly, the apex. Previous results, which 

 were conflicting, are thus brought nearer into line, though they 

 do not show complete conformity. 2 In four experiments the base 

 contracted on the average -031 sec. before the papillary muscles, 

 and the papillary muscles -036 sec. before the apex. There is a 

 variation on either side of these figures of '02 sec. Hering, how- 

 ever, in a preliminary note ( 23d ), states that he finds the papillary 

 muscles contract before either base or apex. Whatever the actual 

 events, the delayed pull of the papillary muscles and chordae 

 observed by Roy and Adami requires explanation, and it appears 

 rational to assume that it is due to delayed contraction, stretching 

 of the chordae, or to a relatively greater shortening of the ven- 

 tricular muscle, and it constitutes evidence that under the con- 

 ditions of the experiment the valves bulge back into the auricle. 



1 Fredericq ( 12B ) makes the same statement. 



1 In some cases Saltzman found the order of contraction reversed or irregular. 



