106 Proceedings of Indiana Academy of Science. 
This test showed: 
1. That the organisms present in this packed sodded land were 
principally slow growers. 
2. That the uniformity of the development of colonies varied with 
the method by which the samples were drawn. 
We have found by numerous tests that the number of organisms 
found in sodded soil at or below a depth of four inches is much less 
than nearer the surface; and, further, it has been observed that those 
organisms occurring at the lower depths do not usually multiply as 
rapidly on aerobic plates as those occurring nearer the surface. The 
samples procured with the bacteriologist’s soil sampler evidently -had 
near their proper proportions of slowly multiplying organisms. 
In testing out the quantities of soil necessary for bacteriological 
examinations some tests were made with air-dry samples to show that 
even when samples were unified by air-drying a large quantity was 
necessary for accurate results. Table III gives the development of 
colonies after different periods of incubation on air-dry soil sieved to 
pass 1 millimeter, while Table IV gives results secured on the same 
sample of air-dry soil when further unified by using only that portion 
passing a sixty-mesh sieve. ; 
TABLE III. 
Percent 6 and 7-Day Counts are of 190-Day Counis. 
(Air Dry Loam Soil, siered C pass 1 mm.) 
Time or INCUBATION 5 7 10 Days* 
Sample No. Size of Sample 
4 é ss =e 
a es 50 grams ee PEE 92.1% 100.0% 
PARAS MCLE 50 grams 79.4 91.2 i 100.0 
ee we ey ae ek oc earn 50 grams 73.0 88.6 100.0 
Bed AES os Fe a 10 grams 87.9 95.0 100.0 
Bhan ee ea aban 2s 10 grams 95.4 96.8 100.0 
(1 Oe A ae nee 10 grams 58.8 85.8 100.0 
1 Regen Ob OI Sarin On, Be 5 grams yale 91.8 100.0 
Noe 2 Ree ; 5 grams 67.8 85.2 100.0 
DP sb tronies oe tive 5 grams 75.8 97.1 100.0 
1 ae Sar aE 1 gram 86.4 95.2 100.0 
1h Le eee are 1 gram 72.1 80.5 100.0 
UD) 8 0 CIEE 1 gram 74.9 80.3 100.0 
[bo be eS Ae Oe Pa A 0.5 gram 64.7 85.0 100.0 
1 ee eee AeA ne 0.5 gram 79.3 85.2 100.0 
A Ae Aer oe 0.5 gram 62.5 79.4 100.0 
Average... 2:45: 74.8 88.6 100.0 
*Counts after 10 days incubation at 20° C taken as 100.0%. 
Other counts states as parts of these. 
Bacterial Dilution 1-400,000. 
