1 82 Journal oj {Agricultural Research voi. xxn, no. 4 



For comparison a special series of samples were prepared by adding 

 5 per cent of meal made from com markedly rotted with Diplodia and 

 Fusarium. In the freshly grouted meal of this series the bacterial count 

 upon plain agar was about 2,600,000. The count of mold colonies upon 

 wort agar was about 1 10,000. About 70 per cent of the bacterial colonies 

 were acid producers. 



After storage for approximately one month (May 20 and 21) samples 

 from a particular lot of five bags of the regular meal showed an average 

 count of 108,000 bacterial colonies and 15,000 molds. Samples from the 

 same bags on June 30 showed an average count of 12,600 bacterial 

 colonies, and 7,600 mold colonies. Without placing emphasis upon 

 exact figures, these cultural results are fairly typical of the mass of 

 figures obtained from cultures made weekly from representative samples 

 involving the whole series of 88 bags of meal. These figures are readily 

 comparable with those obtained from commercial samples (Table I). 

 Discrepancies which occur may perhaps be accounted for by the fact 

 that samples 3, 4, and 5 were evidently the product of local mills, sold 

 fairly quickly after milling, while samples 2, 7, and 9 were clearly the 

 product of special processes and handled under conditions involving 

 much slower distribution. 



In this lot of meal, therefore, the conspicuous change due to storage 

 was the drop in the number of viable organisms to about i per cent of 

 the original number of bacteria and perhaps 10 per cent of the original 

 number of molds. The larger part of this decrease occurred during the 

 first six weeks, with a slow reduction throughout the succeeding periods. 



In connection with the study of these figures, data obtained by Thom 

 and Stiles (unpublished) in examining Winton's {8) samples ^ in 19 14 

 were restudied and compared with the results here considered. Win- 

 ton's com meal varied in initial moisture content from 19.27 to 10.79 

 per cent. In those lots of meal (A, B, and C) carrying moisture mark- 

 edly above 13 per cent, the evidence of multiplication of molds and 

 bacteria was clearly discernible. Musty odors and balls of meal held 

 together by mold were present in every sample. In cultures, the count 

 of colonies of molds and bacteria reached 13 million in the wettest lot. 

 Of these several million were Aspergillus flavus. The predominant or- 

 ganisms were molds rather than bacteria, but there was fairly clear 

 evidence of some bacterial multiplication at the higher water percentages. 



In the roller-gi'ound samples of lots D, E, F, which did not spoil and 

 whose water percentage was near to or less than 13, the total counts 

 found by Stiles approached very nearly those already given in this paper. 

 These examinations began too late in the storage period to show that 

 part of the bacterial flora which dies off rapidly. The stored samples 

 still showed some acid organisms, but micrococci and aerobic spore 



' Samples of the meal studied were examined bacteriologically by G. W. Stiles, formerly of the Bureau 

 of Chemistry, and for mold activity by Charles Thom, then in the Bureau of Animal Industry {8, p. zs)- 



