1111 III'. 



• ricular node and bundle m< ul 15 niiu . 

 J in in. in u idth. 



The real <•!' the tissue i n the auricles and venti 



in nature, although other inections lil<<- th< 



bundle have been described by 



/ ral . runs bel w een the righl auri< 



the righl ventricle. 



Another, bul much Bmaller, n similar embryonic card 



more recently been discovered bj l\«iili ;ni<l Flack in 

 the auricle which correspond anatomically t<> tin 



cold-blooded animals that is, in the area lyii 

 ings of ' he venae cava; and ai ound tl Po be 



explicit, tliis tissue lies "in the buIcus terminalia j 

 formed by the junction <>r the upper Burfaci 

 with the Buperior \ ena ca^ a. "' Tl 



is mon r leas club-shaped, the blunl end of il iub 



shown in the accompanying figure Fig 52 [1 



that there is no direcl connection visible b.-tu .•.•!! th< - 



auriculoventricular nodes Pig 5 ; 



Another anatomic fa< in the a mpanyii 



the disposition of the muscular li : 



bundles in ;i peculi n-shaped manner from a point im- 



mediately below the sinoauricular n< •«!.• t.» all p 



the right auricle. This poinl has I n called I •»»*• 



.v the termination of the venae cava?, the muscle fibi 

 or less circularly . 



Saving become familiar wiili the disposition in the mi 

 uf the j>riiniti\ <• cardiac tissue, along which in the heart 

 animals we knov that the heartbeat spreads, we may nov p 



• hat this tissue 

 origination and propagation of the beat in the 



igin <>t" the beal in .i i 

 it is of course impossible to tell wl 



i. lu>\\ ever, it « ill contin 

 dies it u ill be observed 1 

 ricular ii, and pai 



Biderable tin 



ultii){iim i is situ.ii< il in i 



sinoauricular nod< Tl • ' I i th< 

 tracting do< a i 



which the beat 



• uf the am 



