Abstract
By means of agglutinin-absorption tests, 50% of 83 scarlatinal strains and 18% of 131 non-scarlatinal strains fell into 5 and 8 groups respectively. These cultures were collected over a period of 10 yrs. which may in part account for the small number typed. According to the group precipitin test of Lancefield all except 2 of 418 strains from human beings and animals fell into one or other of 4 groups. This latter classification agrees remarkably well with one based upon biochemical reactions.