2 P. B. MEDAWAR 



apart from these and other particular discoveries, we shall miss 

 him above all for his general comprehension and grasp of all the 

 problems of transplantation. With the Director's warm approval, 

 let us dedicate our present proceedings to the memory of Peter 

 Gorer. 



One of Gorer' s last works was to try to overhaul the termin- 

 ology of transplantation research. We who study transplantation 

 cannot acquit ourselves of the charge of making our ideas known 

 to each other in a terminology that is etymologically ludicrous 

 and inconsistent with certain older immunological usages. At the 

 very least I suggest that we should follow Gorer (Table I) in 

 substituting "allogeneic" for "homologous", and in replacing 

 "isologous" by "isogenic" or, much better, by "syngeneic". 

 Incidentally "enhancement" is another offender. It is a word to 

 which Nathan Kaliss has given an exact meaning : "enhancement" 

 is an abrogation of the homograft reaction mediated through the 

 action of specific humoral antibodies. Where humoral antibodies 

 are not known to be involved, should we not use a non-committal 

 word like "promotion" — Flexner's word, dating from 1907 — 

 instead ? 



At the last Ciba Foundation conference on transplantation, eight 

 years ago, I began with a general review of transplantation theory 

 of which the keynote was our incomprehension or ignorance of 

 much that we should understand or know. No such review is 

 called for today. We have in any event some reason to be satisfied 

 with progress that has been made since we last met here. The 

 serological analysis and genetic dissection of the H-2 locus I have 

 already referred to. Here now, in no particular order, are some of 

 the other accomplishments of the past eight years of research on 

 homografts: the demonstration that, in many inbred strains of 

 mice, male grafts are unacceptable to females — one of the most 

 surprising single facts uncovered by the study of transplantation ; 

 the serological interpretation of "enhancement"; the discovery 

 and analysis of "graft-versus-host" reactions, a discovery which 



