128 THE ROYAL SOCIETY OF CANADA 



formed after prolonged growth, and a dense sediment, pink in colour, 

 subsequently settled to the bottom. 



Because of the marked aerobic character of this organism, tubes 

 of codfish broth were made up similar to the above, with the addition 

 of a strip of filter paper in each tube half in and half out of the liquid. 

 In such tubes a band of red developed on the surface of the paper, its 

 location on the strip depending on the percentage of salt. With low 

 salt content the growth was near the top of the strip, while with 

 higher salt content the growth was nearer the surface of the liquid. 

 This method was found to be simple and was employed extensively 

 for numerous other experiments. 



On 16 per cent, salt codfish agar, or on agar with higher per- 

 centages of salt, the colonies did not develop unless they were on the 

 surface. When freshly plated from the pink fish the growth was very 

 slow, but after isolation and several transfers on salt codfish agar, 

 the colonies grew somewhat better. In both instances, however, 

 growth was slow. The maximum size, 1.5 mm. in diameter, was 

 reached by the seventh to tenth day at 37° C; punctiform, smooth 

 surface, raised elevation, entire edge, and internal structure coarsely 

 granular. Colour varied with the variety, medium and age, from a 

 clear pale pink to a transparent cherry red. When growth was 

 picked off with the needle, the colour was distinctly red and trans- 

 parent. 



Fermentation tubes were filled with 16 per cent, salt codfish 

 broth to which was added two per cent, of the various sugars, glucose, 

 lactose, saccharose and glycerine. Good growth occurred in the 

 open arm with clouding and slight reddening. The liquid in the 

 closed arm remained perfectly clear, and no gas or acid was formed. 



Temperature Relations.- — -Temperature experiments were carried 

 out with the red organisms isolated from all samples of fish received, 

 and for verification, repeated many times. 



The optimum temperature for growth was about 42° C. Good 

 growth occurred at 37° C., and slow growth at room temperature. 



The maximum temperature for growth was 46° C. No growth 

 occurred at 48° C., 50° C, or 52° C. 



The minimum temperature for growth was about 10° C. No 

 growth occurred at 7° C. 



In connection with these experiments a number of tubes were 

 placed eight inches from a sixty watt tungsten lamp, in one case 

 the temperature being 42° C. and in another case 46° C. There was 

 no growth on the 16 per cent, salt codfish agar slope at either tem- 



