58 



the effete blood of the foetus through their ramifications to the pla- 

 centa, where it is oxydizcd from the maternal blood, this becoming 

 deoxydized. The foetal blood now returns along the ramifications of 

 the umbilical vein, and finally is discharged from the placenta by 

 that single trunk. This is a change like that effected in the adult 

 lungs, as is shown by the blood of the umbilical arteries becoming 

 brighter as it passes into the umbilical vein. This oxydation of the 

 foetal blood, by the arterial blood of the mother, causes movement 

 to ensue on the same principles as in the adult lung. 



17. The Lungs. — Anastomosis of the Capillaries of the Lungs. — 

 Dr. Cammann* has given the results of a series of experiments, un- 

 dertaken to show that the capillaries of the lungs do not anastomose. 

 They are sustained, he thinks, by the pathological conditions observed 

 in the organ. The absence of anastomosis admitted, many points in 

 the physiology and pathology of the lungs, are easily explained. 



1st. In pulmonary hemorrhage, the flow of the blood would be 

 kept up continually if the supply was furnished through anastomosis, 

 and no coagulation could occur to arrest it. 



2d. In small abscesses, without false membrane to circumscribe 

 the cavity, a continual flow of blood would occur. 



3d. With a knowledge of this arrangement of the capillaries, we 

 can understand the circumscribed character of pulmonary inflamma- 

 tion, congestion, apoplexy, gangrene, &c, as described by Bayle, 

 Laennec, Andral, Barth, &c, and why inflammation here does not 

 shade off from the centre, but is exactly circumscribed ; and why we 

 may even find spots permeable to air in the very centre of hepatized 

 masses. 



4:th. Why the crepitous rale is often accompanied with respiratory 

 murmur. And perhaps an explanation may also be furnished of the 

 lobular pneumonia in children, and many other important pathological 

 and physiological appearances. 



18. Theory of Respiration. — Dr. George Owen Reesf offers the 

 following theory of respiration: — "The venous corpuscles are known 

 to contain fat in combination with phosphorus. This compound in- 

 gredient of the corpuscles, on coming in contact with atmospheric 

 oxygen, during the respiratory act, is consumed, and combining with 

 the oxygen forms the carbonic acid and water which are expired, 

 and also phosphoric acid, which, uniting with the alkali of the liquor 



* New York Journ. Med., Jan. 1S47. f Proceed. Ecy. Soc., June 3, 1847. 



