Vr R. GREIO- SMITH. 

 Table xv. — Increasing Amounts of Sugar. 



V3 



caused l)y the preseuce of dusters of microscopic crystals of magnesium am- 

 monium phosphate and these are not in evidence in the granular colonies. Large 

 crystals, however, develop slowly in the agai-. and are found in the old plates. It 

 would appear that the development of ammonia runs pari passu with the forma- 

 tion of slime-digestive fennents, for it seems reasonalile to consider that the ropy 

 fubstance was digested as soon as it formed in the case of phase Al(2) with 1 % 

 and 2 % of sugar. With 5 %, the increased sugar resulted in the slime-forming 

 power temporarily overbalancing the slime-digesting power of the bacterium. 



A synopsis of tables v., xiii., and xiv. gives a dearer view of the effects of 

 the various sources of carbon than a detailed reference to the tables themselves. 

 In this sjTiopsis dextrin and gum-aeacia have been omitted because under no 

 circumstances did they ever assist in the formation of ropiness. 



Table xiv;?. -Synopsis of Sugar, etc., Experiments. 



Of all the sources of carbon, galactose seems best fitted to produce the ropy 

 material. This is to be expected since the ro])y substance is essentially a galac- 

 tose anhydride and one would naturally think that the bacteria could form it most 

 easily from this sugar. But the other sugars are not far behind in their capacity 



