690 CARREL— FURTHER STUDIES ON [November 6, 



perform normally their functions. Two weeks after the operation, 

 one of the vessels was examined. The circulation was normal. 

 The transplanted segment looked very much like the other parts of 

 the carotid. It was covered by a normal connective tissue sheath. 

 The wall was of same color and thickness as the wall of the normal 

 carotid. Its consistency was a little harder. Nevertheless, it was 

 found, by microscopical examination, that this wall was composed 

 of an elastic framework and amorphous material surrounded by a 

 new wall of connective tissue. The vessel was dead. The death 

 of the vessel was perh'aps due more to the way in which the desicca- 

 tion was done than to the desiccation itself. With a better tech- 

 nique, results similar to those of Paul Bert could possibly be ob- 

 tained. Actually, this method is dangerous because the artery is 

 not any longer a living structure, but merely a foreign body, as a 

 piece of rubber tubing or an artery preserved in formalin or killed 

 by heating. 



The second method of preserving arteries, outside of the body, 

 consists in lowering the power of the microbian and autolytic en- 

 zymes, by keeping the tissues at a low temperature. This method 

 cannot suspend, for an indefinite time, the occurrence of elemental 

 death. It increases only the length of the period during which the 

 cadaveric changes are slight and not able to interfere with a com- 

 plete, or almost complete, recovery of the artery after transplanta- 

 tion. If a vessel is extirpated aseptically, placed in a sterilized 

 sealed tube and kept in a refrigerator just above the freezing point, 

 it can be preserved for a long time in good condition. From a 

 surgical standpoint, it is sufficient that the vessels are kept safely 

 for a few days outside of the body before being transplanted. 

 Nevertheless, it is far from perfect. The ideal method would be 

 certainly to place the tissues in a condition of latent life, as is pos- 

 sible for Mihiesiiim tardigradum and other organisms. 



The technique that I use is very far from being original. The 

 vessels are merely preserved in cold storage as are commonly eggs, 

 or chickens, or vegetables. They are removed from a living or a 

 dead animal soon after death, perfused and washed with Locke's 

 solution and placed in sterilized glass tubes, the atmosphere of which 

 is moistened with a few drops of water. The tubes are immediately 



