Please note, due to scheduled maintenance online transactions will not be possible between 08:00 and 12:00 BST, on Sunday 17th February 2019 (03:00-07:00 EDT, 17th February, 2019). We apologise for any inconvenience
1. The kinds of bacteria that are isolated by the gelatin plate method from certain river waters freshly polluted with sewage are different from those found in the same water collected a long distance below the point of pollution.
2. In the freshly polluted river water non-chromogenic Staphylococci were found much more abundantly than in the purer waters.
3. In the freshly polluted water the fluorescent bacteria and a group of non-gas-producing, non-liquefying bacteria (Group XI.) were less abundant than in the purer waters.
4. A larger proportion of organisms belonging to the Proteus group were isolated from gelatin plates than from fermentation tubes. The reverse is true of the B. coli and B. lactis aerogenes types. A certain selective influence even upon gas-producing organisms would seem from this to be exerted by the conditions within the fermentation tube.
5. The study of a rather large number of separately isolated cultures belonging to the class of fluorescent microorganisms shows that the differences between the ‘liquefying’ and ‘non-liquefying’ varieties are more constant than is sometimes assumed. The action of these forms upon milk is just as diagnostic as their action upon gelatin. All the strains of fluorescent bacteria that were encountered (58) proved to be motile.
6. Considering as a whole the various physiological tests applied to the several groups of microorganisms, it is found that within almost every group as constituted in the accompanying tables divergence is shown by closely allied organisms in respect to indol formation and reduction of nitrates. The formation of a surface pellicle on broth is also a phenomenon that presents no apparent correlation with more s alient physiological characteristics.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.
To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.
Email your librarian or administrator to recommend adding this journal to your organisation's collection.