The English bacteriologists have also regarded the group of intestinal bacteria, which is propagated by spores, as of equal significance with the colon bacillus. Whether or not every sample of water should be condemned where organisms of this kind are found, as is usually the case, is thought of differently by experts. On the side of safety, it seems to me the only course to pursue is to determine at once by careful investigation the character of the water in which any of these organisms is found. Their mere presence excites a grave suspicion which should be resolved in all cases in favor of the consumer.