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ROYAL SOCIETY OF CANADA 



It was found that the greater the per cent of carbohydrates in the 

 medium, the longer was the growth period. Thus, on agar without the 

 addition of any carbohydrate the growth increased measurably for only 

 6 days; with 10^ of the various carbohydrates the growth increased for 

 8 to 10 days; with 20;^, for 12 to 16 days; and with 30^, for 16 days. 

 The period of active growth was actually somewhat longer, it ended 

 when the band of growth, previously raised, showed a flattened appear- 

 ance due to evaporation of water from the mucilaginous surface. The 

 amount of growth was determined by measuring across the middle ot 

 the band of growth and was approximately as follows : normal growth, 

 or growth on the agar without carbohydrates, 5 m. m. ; restrained 

 growth, 3 m.m. ; increased growth, 6 to 10 m.m., in most cases 10 m.m. 



Effect of Carbohydrates of different Concentrations on Growth 

 and Pigmentation. 



(See special pigmentation of Dextrin.) 



The faint blue pigmentation developed in all except those marked 

 deep blue pigmentation, and the following which produced no color — 

 maltose 20^, galactose 20<^ and 30<^, alcohol and plain agar. 



