SUMMARY:Folpmers' glutamic acid medium and certain modifications of it have been compared with MacConkey's broth for the detection of organisms of the coli‐aerogenes group in water. Very satisfactory results were obtained with the glutamic acid medium made up in tubes and incubated in the same way as with MacConkey's broth. Less satisfactory acid were obtained when lactose was substituted for glucose in the glutamic acid medium, although both were superior to MacConkey's broth. The anaerobic method as described by Folpmers had too many disadvantages to be practicable for the routine examination of large numbers of sample