GRAFTING 425 



twenty-two posterior ends were united and then one of 

 the components cut in two. In five cases a single head 

 developed upon the aboral end of the smaller piece. 

 When several pieces are united, a new head usually 

 appears at the line of juncture. 



Born found it possible to make transverse sections 

 through tadpoles and then reunite them, or to unite 

 the anterior half of one to the posterior half of the other. 

 He also found it possible to unite two anterior portions 

 by their posterior ends, to unite them dorsum to dorsum 

 or ventrum to ventrum, and in the latter case it did 

 not matter whether they were placed head to head or 

 head to tail. 



When sections passing through the organs were made 

 and the fragments coaptated organ to organ, the organs 

 united so that the viscera became functional; when the 

 coaptation was imperfect, the intervals between the 

 organs became filled in with connective tissue, and the 

 ability of the animal to live depended upon the possi- 

 bility of enough functional activity of the mutilated 

 organs being retained. 



Ullmann as early as 1902 transplanted a dog's kidney 

 to its neck, united the renal artery with the carotid 

 artery, and the renal vein with the external jugular vein; 

 the end of the ureter being stitched to the skin. The 

 exact results of this experiment are uncertain. The 

 kidney seems to have remained active for a short time, 

 then degenerated. 



Carrel has found it possible to remove a kidney from 

 a dog, perfuse it with Locke's solution (a physiological 

 solution used to wash out the stagnated blood from the 

 vessels, and so prevent coagulation) for fifty minutes, 

 then return it to normal environment in the same 

 animal, anastomose the blood vessels and nerves, 

 and have the organ continue its function almost indefi- 

 nitely. The following case, one of five experiments, 

 will serve as sufficient proof: "On February 6, 1908, 

 the left kidney of a bitch was extirpated, washed in, and 



