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When this table is compared with Table VI the similarity of 

 results with Sol. E and Sol. H is at once noticeable, the presence 

 of dextrose producing much the same effect as the concentration of 

 the medium by increasing the asparagin content. \Vith the addition 

 of dextrose to a standard asparagin solution, growth is luxuriant in 

 all cases, but although there is an increase of pigment production 

 over Sol. A, where in most cases there was none at all, still the 

 amount of pigment for B. prod. I VI and VIII is at most only 

 a trace. On the other hand, B. prod. VII shows a development of 

 pigment, which at the end of fifteen days is as strong as in the 

 standard solution in three days; and B. ruber indicus I and II 

 show, as in Sol. E, more luxuriant growth with a lessening of pigment 

 production. 



Comparing the effect of the different carbohydrates, we see that 

 saccharose behaves on the whole like dextrose, although in some 

 cases the pigment failed to appear in Sol. K, where it did appear 

 in Sol. H. Lactose gives quite different results. In fact, Sol. I con- 

 taining lactose behaves exactly like Sol. A with no carbohydrates, 

 i. e. pigment is produced with B. prod. VII, B. ruber indicus I 

 and II, B. ruber miquel and B. amyloruber only, these, with 

 the exception of B. prod. VII, showing less luxuriant growth than 

 the rest of the series. This seems an exceedingly interesting result, 

 and falls in line with the conclusion drawn from Table IV, where the 

 color of the pigment gave evidence of the peculiar lack of effect of 

 the presence of lactose. 



It is difficult, even here, to arrive at any general conclusion in 

 regard to the relation of growth luxuriance and pigment luxuriance. 

 As has just been stated, the majority of the cultures showing pigment 

 in Sol. I have grown less luxuriantly than the others. The same 

 thing was true with Sol. A. Again, B. ruber indicus I and II 

 tended to lose entirely their power to form pigment when the growth 

 luxuriance was increased by concentrating the medium or by adding 

 glycerine or sugar. 



These facts, taken in connection with that of less massy growth 

 and more vivid pigment on peptone agar as against the more com- 

 plex meat peptone agar, seem to argue in confirmation of Noesske's 

 and Wool ley's views. On the other hand, Sol. H, in which dextrose 

 induces luxuriant growth, shows pigment, though only traces of it, in 

 fourteen cases, against four cases in Sol. A without dextrose. It may 

 be that here the sugar contributes chemical or physiological aid to 

 pigment formation as well as to vegetative luxuriance. The contrary 

 effect of glycerine points to this conclusion, since here we have 

 luxuriant growth without pigment. 



In this connection also, some of the atypical cultures which have 

 virtually lost the power of forming pigment are interesting. Both 

 B. fuchsinus and B. miniaceus III are among the most 

 vigorous strains of the series in rapidity and amount of development. 

 The latter and B. kiliensis, although colorless, have lost none 

 of their vigor in the fermentation of sugar to gas formation, or in the 



