TRANSPLANTATION OF TISSUES 



1099 



plantation, or graft), or from one animal to another of the same 

 species (iso-transplantation, or graft) has been successfully accom- 

 plished in many cases. But hetero-transplantation, or grafting 

 between animals of different species, is in general not permanently 

 successful, the graft undergoing cytolysis (p. 31) in the alien 

 environment. 



Transplantation, or engrafting, may be done either with or without 

 anastomosis of bloodvessels. In the second method a portion of 

 tissue, usually small, or a small organ, is simply inserted in its new 

 situation without provision for the immediate establishment of a 

 circulation in it. Strips of cuticle may easily be grafted in this way 

 to restore, deficiencies in the skin after burns or extensive opera- 



Fig. 463. Method of Transplantation (of both Kidneys) in Mass (after Guthrie). 

 Segments of the inferior vena cava and abdominal aorta are removed with the 

 kidneys and renal vessels, and interposed in the course of the vena cava and aorta 

 of another animal, according to the method of Carrel and Guthrie. 



tions. The ovary can also be grafted by simple implantation with 

 success. Guthrie has thus shown that hens whose ovaries have been 

 interchanged are capable of laying eggs. When the hens were 

 impregnated and the eggs hatched out the colour characters of the 

 resulting offspring seemed to have been influenced, not only by the 

 hen to which the ovary originally belonged, but also by the hen to 

 which it had been transferred. Grafts of the thyroid and para- 

 thyroid have also been shown to ' take.' 



In transplantation with anastomosis of bloodvessels the main 

 vessels of the engrafted organ are sutured to suitable arteries and 

 veins in the ' host,' so that the circulation is at once effective. Con- 

 sequently there is practically no limit to the size of the grafts. The 



