516 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



been possible to produce homoiogenous immune hemolysins or immune hemag- 

 glutinins in goats, cattle, chickens, and perhaps in some other species, accord- 

 ing to Todd it is not possible to obtain a corresponding formation of homoiog- 

 enous immune bodies in guinea pigs and rats; but these are exactly the 

 species which, above all, have been used in transplantation experiments and 

 this is an additional reason for assuming that in the case of homoiogenous 

 transplantation we have primarily to deal with incompatibilities between host 

 and transplant, and with primary reactions of attack or defense, and only 

 secondarily with immune reactions. 



As we have pointed out above, in those experiments in which individual 

 differences between cells could be demonstrated by serological methods, 

 homoio-immunization was used in the preparation of the immune sera in the 

 majority of the experiments, and in all cases erythrocytes or their derivatives 

 served as antigens. There is, however, at least one instance on record in which 

 apparently hetero-immunization with another type of cells also led to the 

 demonstration of individual differences. According to Dervieux, by means 

 of repeated injections of fresh human sperm into rabbits, antisperm precipitins 

 can be produced, which have the strongest effect on the individual sperm of 

 the donor; here they are effective in the greatest dilution. Dervieux found, 

 furthermore, that the immune serum thus obtained had a stronger precipitating 

 power for strange human sera than immune sera produced by injection of 

 human serum; also, it allowed the distinction between individuals, and even 

 between men and women. However, the spermatic fluid used by Dervieux, and 

 also in the subsequent investigations of Siissman, contained not only sperma- 

 tozoa but also other material, among which were admixed proteins. Therefore, 

 the immune substances elicited by the injection of sperm may readily have 

 been directed against these admixtures rather than against the spermatozoa as 

 such. These experiments were apparently confirmed by Siissman as far as the 

 individual specificity of the sperm antigens, but not of the blood protein 

 antigens, is concerned. But it seems that Siissman carried out only a small 

 number of experiments and not all of these were confirmatory of Dervieux's 

 conclusions, It will therefore be necessary to wait for a confirmation of 

 Dervieux's investigations before his results can be fully accepted. 



More recently, Zangemeister indicated another method by means of which 

 he thought it possible to differentiate between the blood sera even of nearly 

 related individuals. He assumed that following fertilization of the ovum by 

 a spermatozoon and the subsequent formation of the embryo, there develop, 

 as the result of the entrance of sperm material into the blood serum of the 

 mother and of the child, substances which cause a change in the state of 

 dispersion of the serum proteins if the serum of the father is mixed with the 

 serum of the mother, or if the serum of one of the parents is mixed with 

 that of the child. This change in the state of the serum proteins was thought 

 to indicate the relationship between the individuals whose sera were allowed 

 to act on each other. However, these experiments could not be confirmed 

 by Lattes. 



We may then conclude that it is possible to produce specific immune sub- 



