624 



SCIENCE 



[N. S. Vol. XLI. No. 1060 



being permanent as far as eould be made evident 

 by sub-culturing into plaija broth. In these eases 

 observations were made up to two months after 

 the last exposure to the influencing substance, 

 making frequent transfers. There seemed to be 

 no definite rule of reversion, no constant results 

 and no relation between the reappearance of one 

 enzyme and another. The reappearance of the 

 fermenting enzymes in one sugar was not neces- 

 sarily accompanied by those in other sugars. At 

 times the fermentation of one sugar might have 

 returned to nearly normal, while others might show 

 little or no presence of gas with the same strain of 

 B. coli. 



Halophytic and Lime Precipitating Bacteria: K. 



F. Kellerman and N. K. Smith. 



Of approximately 70 cultures isolated from the 

 Great Salt Lake and from sea water from Florida 

 and the Bahamas three types of organisms were se- 

 cured. Pseudomonas calcis,^ a new spirillum and 

 a new bacterium were isolated from the sea water. 

 Closely similar varieties of species of Spirillum 

 and Pseudomonas were found in water from the 

 Great Salt Lake. Both in sea water and in the 

 Great Salt Lake these bacteria are associated with 

 the precipitation of calcium carbonate. 



Belation of Crop to Bacterial Transformation of 

 Nitrogen in the Soil: K. F. Kellerman and E. 

 C. Wright. 

 Progress report upon continuation of work re- 



porteds previously. 



The Influence of Hydrogen-ion Concentrations upon 



the Physiological Activities of Bacillus coli: 



Wm. Mansfield Clark. 



Attention is called to the importance of hydro- 

 gen-ion concentration for the physiology of cells 

 and to to its importance for the solution of vari- 

 ous problems of bacteriological chemistry. The 

 experiments of Michaelis and Mareora upon the 

 limiting hydrogen-ion concentration for B. coli 

 have been elaborated and it is shown that although 

 minor differences exist there is a limiting concen- 

 tration at or above which all activity ceases. The 

 same results were obtained with various cultures 

 of the true colon bacillus. At the limiting 



•2 Kellerman, Karl F., and Smith, N. E., "Bac- 

 terial Precipitation of Calcium Carbonate, ' ' Jour. 

 Washington Academy of Sciences, Vol. IV., No. 

 14, August 19, 1914, pp. 400-02. 



3 Kellerman, K. F., and Wright, E. Claude, 

 ' ' Mutual Influence of Certain Crops in Eolation 

 to Nitrogen," Journal American, Society of Agron- 

 omy, Vol. 6, 1914, pp. 204-10. 



hydrogen-ion concentration proteolysis is inhib- 

 ited. With increase in temperature the effect of 

 hydrogen-ion concentration increases. The rela- 

 tion of this fact to the so-called thermal death 

 point is pointed out. 



An example is given showing the usefulness of 

 the hydrogen-electrode in bacteriological research. 

 By a study of the reaction of the medium at the 

 close of the fermentation it was shown that by the 

 use of p-uitro phenol a separation of the colon 

 arogenes family could be accomplished. The 

 groups so separated were rigidly correlated with 

 the gas ratio. 



Bacteria of the Colon Type Occurring on Grains: 



L. A. EoGERs, William Mansfield Clark and 



Alice C. Evans. 



In an earlier paper it was shown that the colon 

 bacteria of bovine feces belong to a very sharply 

 defined type which was characterized by the pro- 

 duction of a relatively small amount of gas com- 

 posed of hydrogen and carbon dioxide in almost 

 exactly equal parts. A study of the gas produc- 

 tion by 166 colon-like cultures from grains as de- 

 termined under carefully controlled conditions 

 showed that these cultures eould be divided into 

 three physiological groups. These were (1) cul- 

 tures giving a low volume composed of carbon di- 

 oxide only; (2) those giving a low volume and a 

 carbon dioxide-hydrogen ratio of 1.06 and (3) 

 those giving a high volume and a ratio varying 

 from 1.90 to 2.90. The cultures producing a car- 

 bon dioxide only were also distinguished by the 

 rapid liquefaction of gelatin. The low-ratio cul- 

 tures, although agreeing with the fecal type in the 

 gas production, were distinguished by the produc- 

 tion of a yellow pigment. The 151 high-ratio cul- 

 tures were divided into four types. Ninety of the 

 151 liquefied gelatin slowly, gave a carbon dioxide- 

 hydrogen ratio of 2.50 to 2.80, produced a light 

 cadmium pigment, failed to form indol from try- 

 tophane, fermented saccharose and glycerine, and 

 failed to ferment starch, inulin and adonite. 

 Forty cultures failed to liquefy gelatin, gave a gas 

 ratio of 2.20 to 2.50, and produced a light cream- 

 colored pigment, did not produce indol from try- 

 tophane, fermented saccharose, lactose and raffi- 

 nose, but almost always failed to ferment the 

 other test substances. 



Two other groups, differing in their gas ratio 

 and fermentation reaction were made but they in- 

 cluded a relatively small number of cultures. 

 A. Parker Hitchbns, 



Secretary 

 (To be continued) 



