PLATE XXV. 



Showing rate of development of various organ- 

 isms in extracts of marsh soil cropped 

 in different ways. 



u 







■ j i 



£5 







30 



20 



10 



& 



I- 







L 



5. 



c +■ 





Ye/iow ammonifier 



/ dou Z a/ays 3 doys -4 crfartys 



I dCML 



days 3 cVcs"-/? -i days 



Bacillus proreus vulgaris 



fc 



a. 



(/> 



•J* 



•"I 5 



c o 



u 

 



£*o 



10 



I oia<y Z days 



days 4- d&yi 



