8 



TABLE I Concluded 



In forty of the samples the number of bacteria which 

 developed visible colonies on the non-proteid medium were in 

 excess, and in many instances in great excess, of those on the 

 nutrient agar. 



It will be observed that in the remaining thirty samples 

 the number of colonies in the Ashby medium very closely 

 approximate those on the nutrient agar, and in but few in- 

 stances were the colonies on nutrient agar in great preponder- 

 ance. 



As to what is to be inferred from this it is difficult to con- 

 jecture; nor can we conclude that we have here two distinct 

 flora. 



One striking feature which invites attention to the Ashby 

 plate, is the variety of pigments observable. Especially 

 characteristic are the blue, violet, pink, purple, red and brown 

 colors which develop after several days. 



Cladothrix dichotoma, which will be considered later, is 

 one of the most common soil organisms which thrive on a lim- 

 ited nitrogen supply. It is a matter of common knowledge 

 that organisms growing under adverse conditions, or rather in 



