( 379 ) 



ilsclt' |)i-o('isc>Iy in llic moiiiciil in \\liicli il wonld liaxo cominoiK'od 

 if tlio lieai-fs aciioii had hoon distnrhcd ; so tho rhylhni of Iho 

 physioloiiicnl sliniuhilioii is nol distni-ho(h In IIli'. I ') IIk; case is 

 i-(>|>ros(')ilod schonialically. xAn arlificial slinndns f roaches K. Whou 

 Iho s(H'(»nd stiinidns arrixcs il linds tho voniricio slill i-cIVacloi-y ; so 

 oih' s\sloh' is missinu', bnl Iho fodow iiiL»' Ihird sliniidns, canscs jnsl 

 al Iho i-i,Li,hl timo anain a Jiornial systolo. So Iho panso tolhiwini;- 

 tho o,\li-a sysloU' is with rogai'd lo ils chiralion jnst ooniponsatoi-y ; 

 tho tiino takoii np hy a spoiitanoons systoh' -J- oxira s\ stoh> and pause 

 is jnst eipial to that of two normal systoh's. 



II', hoNN'ON'or, we stininhdo tho tVo,<»'s heart at the \-ena oa\a where 

 Iho contraction always sots in, tho conipensalory panse is entirely 

 nussinii' and tho follow ijiu' spontaiioons systole sncceods the extra 

 sNslolo afloi' a pcM'iod ocpial to Iho Jiornial period of coiitiviclion. In 

 b\L>'. 1 tho second artilicial sliiiinlns ^ roacli(\s Iho vena ca\a ; the 

 followijii;' spoiitanoons contraction sets in aftoi- the nsnal inter\al 20, 

 a conipensalory |>anso is missing. Winlsl the intorxal ix'twcon the 

 systole procodinii' the extra systole and the one follouin.ii' ll>o oxlra- 

 syslolo after stimnlation of tiio \-entricle {iw of the anricio) was 

 donhlo the normal period = 40, the same intorxal is here oidy 



12 -1- 20 — :r2. 



I^ 



i Zp 



V ^ 



ju 



1^ 



i J2 I 



z^ 



/<p 



^o 



F..I. 



31 



From this ensues that tho slimnlns is not rhyllnnically induced IVmn 



1) In tlieso sc.liemos ansxvering to those used t'oriiicrly hy Knoki.mann iiihI hy iiir 

 the liine is indicaled on the three ahscissae. aiul this Is done lor IIip diiridioii of llie 

 pliase and llie stimulation of vena cava (IV), auricle (^l) and ventricle (T). \ — 

 pliysiologicid stiinidus, $ = artificial sliuiulus. The perpendicular lines represonl llie 

 conlractions of the heart-cavities. The slanling lines connecting the hase points of 

 the systole-mark indicair' the direction in xvliicli the stimulus is conducted. If 

 those lines are dolled the conduction does nol aclually lake place. The duration 

 of lh(.' sponlaneous period is puf al -Jd ahscis units ( - 1 niM.), the interval from 

 the moment of the physiological sliuiulus lo llic vfulriciilar contrucüon ( W I'aJ = «J 

 uuils. 



