Habitat.—Intestinal canal.

Natural vectors.Blatta orientalis, Poland (Nicewicz et al., 1946): Isolated from intestinal tract.

Alcaligenes viscosus (Weldin and Levine) Weldin

Habitat.—Water, dairy utensils; produces ropiness in milk.

Natural vectors.Blattella germanica, U.S.A. (Janssen and Wedberg, 1952): Isolated from intestine and feces.

Family ENTEROBACTERIACEAE

Aerobacter aerogenes (Kruse) Beijerinck

Synonymy.Bacillus lactis aerogenes.

Habitat.—Grains, plants, intestinal tract of man and other animals.

Natural vectors.Blaberus craniifer, U.S.A. (Wedberg et al., 1949): Isolated from feces.