1. Investigation by American bactriologists have shown that the lactose-fermenting (gas-producing) bacilli can be divided into two main types distinguishabel by the methyl-red and Voges-Proskauer reactions.2. The methyl-red- Voges-Proskauer + type are shwon to be rare in human and animal faeces, more common in surface water, milk and sewage, and the predominant type in soil and grain, and to be more resistant than the methyl-red + Voges-Proskauer-type.3. Investigations by the author of this paper confirm their findings as regards human and animal faeces, water, milk and grain. An investigation of the types present in soil is being undertaken and it is hoped to publish an account of this later. Already the “M.R.—” type has been found to predominate in four out of six samples of soil.4. In the present investigation organisms of the “M.R.—” type were found in 66 samples of water out of a total of 200 containing lactose-fermenters, and in 41 samples containing this type no evidence of recent contamination could be adduced by the search for organisms of the “M.R.+” type ofStreptococci. Judgment of the water was therfore liable to modifiction in 20% of these samples by the recognition of this type.5. Twenty-nineout of the 66 samples containing organisms of the “M.R.—” type were from sources of good repute, most of them from public supplies.6. The presence of lactose-formenters of the “M.R.—”“V.P.+” type must be regarded with considerable less disfavour than the presence of “M.R.+” “V.P.—” organisms, and the application of tests for the recognition of these types is impotant. It is suggested that these tests should be included in all routine examinations of water and food products.In conclusion I have pleasue in acknowledging my indebtedness to Dr. W.G.Savage for calling my attention to the reserches of American bacteriologist and for many valuable suggestions he has made in connection with this work.
Correction: Lewandowski, J., et al. Groundwater–Surface Water Interactions: Recent Advances and Interdisciplinary Challenges. Water 2020, 12, 296
