98 Proceedings of Indiana Academy of Science. 
TABLE JI—Continued. 
Colony Counts on Plates of Different Bacterial Dilutions Cover Crop Investigations. 
Average of Triplicate Plates. 
PLor SupportTinG 
Dilution 1-40,000 Dilution 1-400,000 
Nothing 
Novemberni4s 101d ta sccm semicon ae ae Se 62105 "= 6iose 
NebruarysO nol ote tence eee ae aoe : 93.0 : 17.3 od 
Marek 2alOlon torn eee e ke ae meee é ie Se 1805 11843° < 
March 7a DUlo'.e ns signaan cris ene i I ee LAS 43.0) = 3.0* : 
ATI TIL aL OLD area cla nev hie eae oe re es Ae i 96.0 ‘ 9.7 st 
Buckwheat 
November 14, 1914. . heroes : 50.0 10.3 a 
iebruary? 6, Lolo: ss cslht Sele ae vere ABA See 121.3 21.3 - 
March ic l0lo ssa ee see ep oter eae oat : 163.0 : 150" a 
March 27, 1915....... Lae =e : 86:0) <9 * 6.4 2 
April 5: TOVGe. etnies. : : ci ere 119.7 - 14.0 2 
Natural Growth of Weeds 
November 14, 1914... SEW ate rete s 54.7 . aa hata 
February 6, 1915... A gn eras Pac TOO SSA ees PRE se 
Mareh'2, 1915... 2.2... navi ; | 1§2:5 33.6 = 
March 2/1 ULor os Amee cts reer 1 82.3 vi 11.0 eg 
Mpcileth Glo cten eRe Ice oe, et a eewtOSOwn = Te) 
Average of all 60:comparisons.........65-- 205-2 secre eee é Ua eH 14.8 - 
ALVerag eo OL sla COMpATINOUS! Ac scr is2. Ae ete «PF oe wie Fee are tele 94.4 * 9.4 mS 
These results show: 
1. The ratio between the number of colonies on plates from the 
1—40,000 and 1-400,000 bacterial dilutions is dependent on 
the number of organisms present rather than on the crop- 
ping system or the time of the year the soil samples were 
taken. 
2. The averages show: 
(a) That the average of all comparisons for the 1—40,000 
bacterial dilutions was too great for satisfactory 
plates. - 
(b) That the results from the two dilutions tend to check 
when the number of colonies on the plates from the 
1—40,000 bacterial dilutions is under 100. 
