H. 15. Hutchinson and J. Clayton 101 



Table VI. 



Inhibitorij Effect of Dextrose on the Growth of S. cytophaga in 



the Presence of Cellulose. 



Concentration of solution (per cent.) 



Growtli I * -^ 



after Control 0005 001 0025 0050 010 0-25 0-50 100 



3 days ++ ++ -+ -+ - - - 



8 days + + + + + + + + + -+ - + 



12 days + + + + + + + + + + + + + + 



A further series was designed to sliow the difference in inhibitory 

 power of two bioses, viz. saccharose and maltose, in the presence of 

 cellulose. In the following table the records refer to actual growth but 

 not to intensity of growth as in the other series. 



Table VII. 



Relative Inhihition of Growth by Saccharose and Maltose in the 



Presence of Cellulose. 



Concentration of solution (per cent.) 



. A — ^ 



0004 0009 0-018 0037 0075 0-15 0-31 0-62 1-25 2-50 10-00 



.Saccliaro.se i days + + + + + + + ---- 



G „ + + + + + + + -!- + -- 



9 „ + + + + + + + + + -- 



Maltose 4 days ______-__-- 



«., + + --------- 



!)„ + + + -------- 



The striking difference in effect of a reducing and a non-reducing 

 sugar is well brought out, the critical' concentration of maltose being 

 in the region of 0-018 per cent., and of saccharose approximately 1-25 

 per cent., i.e. a ratio of 1 : 70. So far as we are aware, this .specific 

 susceptibihty is quite unique. 



Having determined the behaviour of the organism towards repre- 

 sentatives of the carbohydrates, it was decided to proceed to an examina- 

 tion of the value of a number of organic acids as sources of carbon. 



The general plan was similar to that adopted in the case of the 

 carbohydrate series, i.e. cultivations were attempted in the absence 

 and presence of cellulose. As we were in poi5session of a number of 

 calcium .salts of certain mono- and di-basic acids it was most convenient 

 to carry out the tests with these. Unfortunately, the use of calcium 

 salts introduces a serious complicating factor in that, as the solubility 



Joum. of Agrio. Sci. ix H 



