154 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



tween donor and host ; there are others, as, for instance, Lexer and Holman, 

 who were unable to discover a relation between the compatibility of blood of 

 donor and host and the result of grafting, and there are still others who do not 

 hold that identity of the blood groups makes the homoiogenous transplantation 

 of skin fully successful, but who still find indications that the sameness of the 

 blood groups at least delays the destruction of the homoiogenous grafts. 



In appraising the value to be attached to these divergent results, it seems 

 that surgeons, with the largest experience in skin grafting, and among them 

 those who have carried out these transplantations more recently, have ob- 

 tained as a rule entirely negative results, while especially some earlier work- 

 ers, with more limited experience, who did not follow the fate of the trans- 

 plants over longer periods of time, believed that they had obtained confirma- 

 tory results; as to the latter, however, there always remains a doubt as to 

 whether the definite healing-in of the transplants was actually seen, or whether 

 the transplants were not gradually replaced by the adjoining skin of the host in 

 cases in which there was compatibility between the blood groups of donor 

 and host of the graft. More convincing then these earlier experiments are the 

 experiments of transplantations in animals ; especially the very careful in- 

 vestigations of Kozelka, in which skin of fowl was used for transplantation, 

 are significant in this respect ; no relation between the agglutinogens present in 

 the erythrocytes of host and donor and the success of the transplantation was 

 noted. Likewise in the work of Ingbrigtsen, who transplanted segments of 

 arteries in cats, and that of Haddow, who transplanted sarcoma in fowl, the 

 findings were independent of the agglutination reactions between the blood of 

 donor and host. We believe, therefore, that the evidence available at present 

 makes very improbable a direct relationship between the four primary blood 

 groups and the individuality differentials of host and donor. Correspondingly, 

 we must conclude that there is no definite correlation between the results of 

 transfusion of blood and those of homoiogenous grafting of skin. There seems 

 to be no more reason for assuming that the particular genes determining the 

 four blood groups determine also the fate of homoiogenous transplants than 

 for believing that the identity of heterophile antigens, among different classes 

 of animals, makes heterotransplantation between these classes possible. 



However, in recent experiments, Sandstrom made some observations of a 

 different nature, which suggest to him a relation between organismal differ- 

 entials and blood group antigens. Implantation of a piece of macerated meta- 

 nephric tissue of the duck on the chorio-allantoic membrane of the chick 

 caused the death of the chick, provided the donor of the implanted tissue was 

 near the stage of hatching or had hatched. Neither implantation of non- 

 macerated tissue nor of macerated chick kidney to the chorio-allantoic mem- 

 brane of the duck had this effect. Other kinds of macerated duck tissue have 

 apparently not yet been tested. Sandstrom believes that the death of the chick 

 in this experiment was caused by an agglutination of erythrocytes within the 

 blood vessels. However, it is not certain from his report whether the occlusion 

 of the vessels was due to a pure agglutination process or whether coagulation 

 processes had been involved in this effect; it seems possible that it was due 



