( 82 ) 



sensibly rei lured. In the first only slightly weakened \' s only a 

 part of the ventricular musculature could contract as a result of 

 this disturbance of conduction. In the following contraction of the 



ventricle the wave spreads, however more slowly than in the 

 normal cases hence the stretched form of I') over the entire 

 ventricular musculature. As the conduction of the contraction wave 

 can take place after the modern doctrine of (taskkli. and ENGELMANN 

 in all directions, the contraction wave in this case winds its way 

 through this lengthened 1"- to arrive antiperistaltically again at the 

 auricle. After this only a pari of the ventricular musculature has 

 regained its conducting (tower sufficiently and a weakened I" will 

 join the antiperistaltic A s . Ii is clear, that on account of the 

 antiperistaltic contraction the wave from A to V, to A again ; from A 

 returning to another limited part ot' I'; then again to A, etc. will 

 give rise to a pulsus alternans, in this case temporarily, whereby 

 the interval between the commencement of the great contraction 

 and that of the smaller one, is smaller than that between the 

 small contraction and the greater contraction. One can among the 

 dyalisata-experiments recognise these cases there, where after a 

 maximal toxic dose the frequency first became considerably slower, 

 but finally quicker again. Whereas in the vena cava curve previously 

 the pulsations of the sinus were easily visible, one does not find 

 any indication ot' sinus contraction after the premortal pulse accele- 

 ration has sei in. 



We find therefore here a form of cardiac activity, which shows 

 the same particularities as the P. A. formerly described by the 

 writer for the poorly nourished frog-heart (Loc. cit. 1902) of which 

 however the mode of origin was quite a different one. 



The only objection, which can be adduced against this interpre- 

 tation, is a theoretical one. Until now, it was looked upon as a 

 dogma, that the unimpaired ventricular musculature under no cir- 

 cumstances shows the phenomena of dissociation. This dissociation 

 between the different heart cavities and in every one separately, was 

 explicitly described by the writer in several publications l ), especially 

 regarding the sinus; its significance for our understanding of nerve 

 influence on the heart, was more than once urged. Although in these 

 experiments and those of ENGELMANN the occurrence of similar dis- 

 sociations also of the unimpaired ventricle had to be acknowledged, 

 the direct proof of its existence as far as I know, has never been 



'i Geneesk. bladen 1897. p. 75. Proceedings ot the American Academy of Arts 

 and Sciences 1898. Vol. XXXIII. No. 71. p. 188. Americ. Jnl. of Physiol. 1898. 

 p. 503 seq. N^l. Tijdschr. v. Geneesk. 1898. Deel 11. lil/.. 57:2 and 1902 Deel 11. 

 Biz. 583. 



