AN ANATOMICAL STUDY ON THE 



lungs transmitted air to the heart, in the living dog. 

 On inflating the lungs of a cadaver in an anatomical 

 demonstration, who doubts the air could be seen 

 going this way if such a passage exists? This func- 

 tion of the pulmonary vein, the transmission of air 

 from the lungs to the heart, is considered so signifi- 

 cant that Hieronymus Fabricius of Aquapendente 

 insists the lungs were made for the sake of this 

 vessel' and that it is their most important structure. 



I would like to know why the pulmonary vein is 

 built like a vein if it is destined for the transmission 

 of air. 



It would be more natural for it to be made of 

 ringed tubes such as those of the bronchi, in order 

 always to be open and not liable to collapse. Thus 

 it might remain free from blood with no liquid to 

 hinder the passage of air, as may sometimes be 

 noted in the lungs when they labor under more or 

 less phlegm in the bronchi, when breathing is sibi- 

 lant or strepitous. 



Even less tolerable is the opinion which supposes 

 two materials, air and blood, necessary for the forma- 

 tion of vital spirits. The blood is supposed to ooze 

 through tiny pores in the septum of the heart from 

 the right to the left ventricle, while the air is drawn 

 from the lungs by the large pulmonary vein. Accord- 



' Not quite as respectful of Fabricius (i 537-1619) as one would 

 expect in a devoted pupil. For a translation of the passage referred 

 to (De Respirationeyi6o2), see M. Foster's famous History of Physiology, 

 Cambridge, 1901, p. 38. 



20 



