THE UNIQUENESS OF THE INDIVIDUAL 



exchanged between identical twins on a scale limited only by 

 the exigencies of surgical technique. For the purpose of trans- 

 plantation, identical twins behave as if they were a single 

 individual — as indeed they once were, for both arose from a 

 single fertilized egg. Skin grafting has just once been used to 

 clear up a problem of disputed parentage.^ One day the father 

 of two six-year-old boys Pierre and Victor (HI s^agit ici de 

 pseudonymes'') had his attention called to a third small boy who 

 was reported to be the very image of his Victor. The third boy, 

 Eric, had been born in the same clinic and on the same night; 

 it seemed possible, therefore that Eric and Victor were twins 

 and that the children had somehow been muddled up. A very 

 careful character-comparison undertaken by Professor Frances- 

 chetti made it all but perfectly certain that Eric and Victor 

 were indeed identical twins, and at least likely, therefore, that 

 Pierre really belonged to Eric'*s putative mother; but this was 

 an hypothesis which she was unwilling to entertain. Blood 

 grouping tests of some refinement now revealed that Pierre 

 could not have been the son of his alleged mother, but without, 

 unfortunately, excluding the possibility that Eric was his 

 alleged mother's son. (Eric'*s father was dead.) In this predica- 

 ment. Sir Archibald Mclndoe was asked to perform a test by 

 which the case would be agreed to stand or fall: small skin 

 grafts were exchanged on the one hand between Pierre and 

 Victor and on the other hand between Victor and Eric. The 

 skin grafts exchanged between Pierre and Victor were de- 

 stroyed and sloughed away in a matter of weeks; those ex- 

 changed between Victor and Eric survived over the whole 

 period of observation and presumably survive still. These tests 

 can be taken as a proof that Victor and Eric were twins, and 

 under the circumstances, a proof of 99*9 per cent certainty that 



1 A Franceschetti, F. Bamatter and D. Klein, Bull. Acad. Suisse Sci. 

 Med., 4, p. 433, 1948; A. Mclndoe and A. Franceschetti, Brit. J. plastic 

 Surg., 2, p. 283, 1950. 



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