OTTENBERG AND BERES 



919 



allelomorph hypothesis as proved until enough genetical data are accumulated to 

 compel its acceptance.' 



HEREDITY OF NEW AGGLUTINABLE FACTORS IN HUMAN BLOOD 



Entirely new vistas of investigation have arisen with the recent discovery of new 

 agglutinable factors in human blood, by Landsteiner and Levine.^ By absorbing a 

 number of anti-human-blood immune sera from rabbits with the blood corpuscles of 

 certain individuals, regardless of the group, fluids were obtained from a few sera 

 which gave a sharp differentiation of individual human bloods within the common 

 blood groups. A number of such factors have been found which are arbitrarily des- 

 ignated as M and P. It is possible to divide humans into M-positive and M-negative, 

 or into P-positive or P-negative, individuals. A somewhat higher incidence of M 

 among colored than white individuals was found. The heredity of the M factor has 



TABLE IX 

 Heredity of the "M" Factor 



been studied by Landsteiner and Levine-' in more than one hundred families. Their 

 results are in keeping with the assumption that M is inherited as a Mendelian dom- 

 inant. In Table IX the families are arranged in three classes according to the presence 

 or absence of the factor M in the parents. 



The significance of the facts of the inheritance of the iso-agglu finable blood ele- 

 ments in the biology of man invites consideration. It is the desire of the student of 

 genetics to establish for the organism with which he is working its genetic composi- 

 tion, to draw on a chromosome map the positions of the genes, as T. H. Morgan and 

 his co-workers have done for the fruit fly, Drosophila. Whether the forty-eight chro- 

 mosomes of man will ever be charted so, no one dare say. But in order that it be done, 

 the linkage relationships of hundreds of characters, whose inheritance will permit 

 simple Mendelian analysis, need to be studied. Thus far, no example of linkage in 

 humans has been described. 



So universal a character as the blood group offers a vast field for the study of 

 linkage, and the possibilities are multiplied many times when the new agglutinable 



' A. A. Mendes-Correa (Le Sang, i, 322. 1927) in a paper which appeared since the preparation 

 of this article claims that Bernstein's mathematical assumptions are based on an identity and are 

 therefore not valid. 



^Landsteiner, K., and Lavine, P.: Proc. Soc. Exper. Biol. &° Med., 24, 600. 1927. 



^ Ibid., p. 941. 1927. 



