140 



The Ohio Naturalist. 



[Vol. X, No. 6, 



TABLE I. 



Transpiration Data for Solutions Inoculated Nov. 14, 1909, With 

 Pure Cultures of Bog Bacteria. 



Using the transpiration of the controls as a basis and repre- 

 senting it as unity the different bacterial cultures have values 

 in the order as indicated in the last two columns of the table. 

 These figures show conclusively that in all cases the bacteria are 

 responsible for the proportionallv diminished transpiration and 

 growth. The transpiration values fluctuate to a considerable 

 extent ; in some cases the differences from the controls are not so 

 very great, but in all cultures the values lie below that of the 

 control. 



The evidence derived from the duplicate series is omitted, 

 showing, as it does, results as closelv parallel as in Table I. 

 To what extent Table II suggests the possibilitv that bacterio- 

 logical diagnosis when correlated with physiological criteria 

 may determine the crop-producing power of dift'erent soils need 

 not be discussed at length. The figures speak for themselves. 

 Several facts, however, seem to be clearly brought out in the 

 above data. The transpiration figures of the first five days in 

 B. 25 and B. 1 cc. indicate that the growth of the plants was 

 considerably stimulated by the presence of the toxic bodies in 

 the solution. Those of the last five days prove that the solution 

 was decidedly injurious. B. 13 is worthy of note since the plants 



