288 



Blood Groups 



contain an agglutinin known variously as ao or as anti-0 since 

 it appears to react with type blood and less strongly with 

 certain bloods containing on A2 agglutinogen. One theory has 



TABLE 12 



Results of Crosses between Various Combinations of Genotypes 



FOR the AB Blood Groups 



Results of reciprocal crosses are the same. 



been advanced that the anti-0 agglutinin is really directed 

 specifically against type blood. According to this theory, 

 this agglutinin agglutinates 00 blood (group O). In bloods of 

 group Ai which are genotypically AiO (or P^i), this anti-0 

 serum causes no agglutination presumably because gene Ai (/^^) 



