The Streptococcus lacticue group originally proposed by Kruse in 1903 had almost unlimited boundaries and would include practically any nonpathogenic milk souring streptococcus. Today, the group is interpreted in much the same way by many authors. However, notwithstanding the fact that the so-called lactic group may be a most inclusive collection, there is a possibility that the present treatment is somewhat too indefinite to furnish a basis for the answer of a number of questions of biological and economic importance.