CHAPTER XVII. 

 GRAFTING. 



By grafting we understand the implantation of any 

 portion of living tissue into the same or another position 

 in the same organism, or into the same or a different posi- 

 tion in some other organism. 



The results are found to vary according to the nature 

 of the tissue transplanted, the character of the tissue 

 into which it is transplanted, the ages of the respective 

 tissues, the physiological importance of the transplanted 

 tissue, the physiological necessity the organism experi- 

 ences for it, the ability of the transplanted tissue to 

 maintain itself during the period of malnutrition follow- 

 ing the transplantation, and the blood-relationship of 

 the respective organisms whose tissues are concerned. 



The general facts bearing upon grafting apply to both 

 the vegetable and animal kingdoms. 



1. The amputated part is immediately returned to its 

 normal environment. 



Under these circumstances the least possible amount 

 of disturbance is effected, and it can be imagined that 

 if, in the replacement of the removed tissue, a sufficient 

 amount of care is exerted in approximating the tissues, 

 there is no essential difference between such an opera- 

 tion and a simple incision. Indeed the experiments of 

 Carrel have shown that the chief difficulty is in restoring 

 the necessary circulation, and that if this can be success- 

 fully overcome by end-to-end anastomosis of the blood 

 vessels, whole limbs may be removed from animals as 

 highly and complexly organized as cats and dogs, and 

 successfully replaced or even exchanged. With the cir- 



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