IMPROVED. S7 



Lungs) and the right Auricle; the other, paffes 

 between the two Auricles : Thefe Airround the En- 

 try both of the Aorta and left Ventricle. 



The Entry of the right Ventricle is alfo tendi- 

 nous, but all the Fibres w^hich terminate about 

 the Pulmonary Artery terminate flcfhy. 



Now of the Fibres which fpring from the right 

 Ventricle and Pulmonary Artery, the Oatermoil, 

 which are by much the finell, go in a llraight Line 

 to the Point of the Heart. All the others, which 

 are next the Surface of the Heart, wind towards 

 the left Hand, till they arrive at the Point, 

 where turning underneath themfelves, and under 

 the right Ventricle, they wind up the left Ventricle 

 towards the right Hand to their Infertion in the 

 Bafis. Under the llraight Fibres there pafs a few 

 more almoft ftraight, from the Mouth of the right 

 Ventricle to the Pulmonary Artery ; and from the 

 oppofite Side of the Artery, to the fecond Tendon 

 of the Aorta, there pafs others; by both which 

 the Mouth of the Pulmonary Artery is dilated in 

 the Contraftion of the Heart. Under all thefe, 

 fome which wind from the flrft Tendon of the 

 Aorta towards the Point, when they come to the 

 Middle of the right Ventricle, turn up again to 

 the Root of the Pulmonary Artery, or terminate 

 in the ilefhy Pillars and Papilite. Thefe both con- 

 tra«Sl the Ventricles, and dilate the Arteries at 

 the fame time. 



The Mouths of the Ventricles are likewife fur- 

 rounded with Semicircular Fibres, which affift the 

 Valves in the Syjiole or Contradtion of the Heart, 

 On the Side of the Septum medium (which is next 

 the right Ventricle) fome. Fibres go flraight from' 

 the Bafis to the Apex or Point. All the Reft of 

 the Fibres are only twilled round the Ventricle, and 

 oi thefe fome creep halfway, fome more than half 

 way, and then return to the Bafis by the oppofite' 

 Sice ; fome again terminate in the flefhy Pillars and 

 Vapilla ; the Reft turn the point and fecm to involve- 

 • - D 5 the 



