1. B. coli (Escherich) produces papillated colonies and shows marked variability in the size of its colonies whenit is grown on agar to which phenylacetic acid has been added in the form of the sodium salt.
The big and little colonies produce about the same amount of gas when tested on glucose.
2. When B. coli (Escherich) is grown on agar containing monochlorhydrin it throws off variants similar to those produced when grown on monochloracetate of soda media. Speaking broadly they ferment alcohols with gas formation, and sugars without gas formation.
3. B. lactis aerogenes grown on monochlorhydrin agar gives rise to variants unable to ferment glycerine.
4. In cases of inhibitory bacterial selection by chemical agents a careful comparison of the surviving cells with the orginal strain from which they were derived is calculated to indicate that portion or function of the cell which is implicated in the cell's intoxication. This question does not seem to have been attacked hitherto from this standpoint.
5. The cell ferments by virtue of their specific chemical affinities mayplay a part in cell intoxication.