Chapter 16 



The Relations Between Processes of Immunity and 

 Individuality Differentials in Transplantation 



The observations made by surgeons and by experimental biologists, 

 which showed that in man and in higher animals autotransplantation 

 succeeds much better than homoiotransplantation of various organs 

 and tissues and that heterotransplantation never succeeds, gave rise to various 

 interpretations as to the cause of these differences. In tracing the develop- 

 ment of these interpretations it is interesting to note that they depend largely 

 on two factors. In the first place, the discoveries made and the systems of 

 thought built up in different fields of science are seen to be related to par- 

 ticular problems certain analogies are observed or are assumed to exist be- 

 tween two different series of investigations and the conclusions of the one are 

 applied, with some modifications, to the other. Secondly, new experiments 

 are carried out in order to analyze a problem by a direct approach, but here, 

 also, the interpretation may be influenced by analogies with conclusions ar- 

 rived at in the related science. These two factors are clearly discernible in the 

 search for an answer to the question as to why homoiogenous transplanta- 

 tions do not as a rule succeed. Towards the end of the last and in the be- 

 ginning of this century, the thoughts of pathologists, in their analysis of 

 transplantations of organs and tissues in higher animals, were influenced by 

 the investigations of experimental biologists, who grafted tissues in lower 

 animals and plants and who found polarity in the structure of the organisms 

 to be a factor in transplantation, and who also observed that the character of 

 the tissues adjoining each other in host and transplant was of great signifi- 

 cance in determining the compatibility of grafts and hosts, and it was main- 

 ly for the purpose of discovering polarity and other related factors as deter- 

 miners of normal structures that biologists carried out experiments in graft- 

 ing. Such an influence is noticeable in the work of the pathologist Marchand 

 on transplantation in higher animals and in man, in the writings of Lubarsch, 

 and also to some extent, in those of Schoene. Then in the beginning of this 

 century, the differences between the results of autogenous and homoiogenous 

 transplantations of tissues and tumors in higher vertebrates were inter- 

 preted as due to the various degrees of compatibility or incompatibility be- 

 tween the chemical composition of the bodyfluids of the host and of the 

 transplanted tissues. This interpretation was suggested by us, and the im- 

 portance of the biochemical constitution of host and graft was also empha- 

 sized by Borst, who believed that inadequate biological systems may cause 

 atrophy and loss of function of transplanted organs; Borst considered, in 

 addition, the effect of cytolysins and anaphylaxis, assuming that such factors 



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