142 
The Ohio Naturalist. 
[Vol. X, No. 6 
noteworthy characteristic than structural deviations or acclima- 
tization. Much economic value would attach to an extension of 
these experiments by determining through selection and a more 
detailed physiological study the cultivated forms resistant and 
immune to the effects of this type of soil bacteria, and the nature 
of the resistance. 
In order to determine the ability of the micro-organisms to 
convert soluble proteids into amido-acids and allied products 
from the decomposition of proteids enough peptone was added to 
solutions of sterilized bog-water and peat to make an equivalent 
of a 1% peptone culture. After sterilization the solutions were 
inoculated with the bacteria indicated in Table III. The cul- 
tures were then tested physiologically at the end of a two-weeks 
incubation. Since the danger of contamination becomes 
increasingly greater with peptone cultures, the transpiration 
figures for only the first five days are tabulated. They are 
believed to be entirely consonant with the true state of affairs 
since the figures in the duplicate cultures appeared in every way 
parallel. The wheat plants had grown in each experiment for 
three days at the time the photographs here added were made for 
the writer by Prof. Schaffner. 
TABLE III. 
Transpiration Data for 1% Peptone Culture Solutions Inoculated 
Jan. 15. 1910, With Pure Cultures of Bog Bacteria. 
Series IX 
Number 
Bacteria 
Transpiration In Grams 
5th Day 
(Feb. 4th) 
Comparative 
transpiration 
Percentage 
decrease 
6 
Control 
17.65 
100. 
0. 
7 
Pep. chk 
7.00 
39.65 
60 . 35 
13 
B. 13 
4.85 
27 . 47 
72 . 53 
14 
B. 25 
2.70 
15.30 
84.70 
11 
B. 2 
2.30 
13.03 
86.97 
12 
B. 4 
2.40 
13.60 
86.40 
15 
B. 1 cc. 
1.87 
10.60 
89.40 
A brief inspection of the figures and the photographs suffices 
to show that transpiration, growth, green and dry weight of 
wheat plants are in this case proportionally reduced. Compared 
with the weekly atmometer readings it is evident that transpira- 
tion is not merely a function of absorption and of growth but also 
a function of the rate of evaporating power of air, that is the 
saturation deficiency of air. The rate of transpiration is seen to 
be the product of a co-ordination of factors. It is not due to 
any single factor but to the cumulative action of several 
conditions. 
