184 Journal of Agricultural Research voi. xxii. no. 4 



and 15,000 molds. This observation was confirmed by a restudy of 

 Stiles's unpublished examination of Winton's (8) samples. Of every 

 lot of com handled, part was ground in a stone mill without sifting or 

 bolting and part was carefully " degerminated " and "roller" ground. 

 In the bolting process all of the bran was taken out, and many of the 

 samples consisted almost completely of homy endosperm. In that part 

 of this series made up of meals in which no multiplication of micro- 

 organisms occurred, bolting consistently reduced the cultural count of 

 microorganisms below that of the stone-ground meal. Frequently the 

 number found in the bolted meal was less than one-tenth of that in the 

 stone-ground meal. 



By removing the bran, bolting takes away the largest area of contami- 

 nation with saprophytic organisms. The tip of the kernel and the 

 germinal area carry the majority of the infections found in com. Study 

 of many samples of com over a period of years shows that invasion of the 

 germinal area by molds is not uncommon in com which has not been 

 fully matured or has not been promptly and thoroughly dried. Sam- 

 ples have frequently shown the invasion of the germ in every kernel by 

 Aspergillus repens. Recently samples representing a bulk shipment 

 have shown nearly every grain to contain one or the other of two species 

 of Penicillium. Meal therefore may be so milled and sifted or bolted 

 as to remove the larger part of all contaminations, as well as those mold 

 infections which do not involve general disintegration. The cleaning 

 process before milling removes the grains thoroughly rotted by Fusarium 

 and Diplodia. Corn has still been seen going into the rolls of a mill 

 in which the low grade of the stock could not have been concealed if it 

 had passed through a stone mill without being bolted. The product, 

 however, was going into human food without showing tangible evidence 

 of the low quality indicated by the unground grain. In other words, 

 the fractional milling of low-grade grain makes possible such separation 

 as turns the infected portions of the grain into oil stock or cattle feed 

 and the solid or homy portions which are less obviously damaged into 

 meal. 



The literature of maize deterioration is reviewed by Alsberg and Black 

 up to 19 13 (7). The activity of Fusarium and Diplodia as causes of 

 rotting in ear com was discussed by Burrill and Ban-ett (5) and that of 

 Diplodia alone by Heald, Wilcox, and Pool (4). 



More recently McHargue (6) has studied the activities of certain fungi 

 and their relation to commercial conditions in the handling of the product. 

 Excessive moisture in the grain is regarded as the limiting factor in most 

 cases of such spoilage. The factor of temperature must not be over- 

 looked. The moisture content limit may be materially increased during 

 the winter without evidence of the activity of microorganisms. The 

 agents of spoilage in all the cases under review were primarily molds. 

 The results already given in this paper harmonize in general with those 



