ORGANISMS OF SANITARY SIGNIFICANCE ON GRAINS 215 



of us in western Massachusetts, which, owing to the scanty growth, 

 had not been cut. The field is of light soil, on a sandy, level, open 

 plain, and situated well back from a little-traveled country road, 

 and far from human habitation. Inquiry showed that the field 

 had not been fertilized, and that no cattle had ranged through the 

 grain during the year. This stand of grain, therefore, may be 

 taken as a typical open-country growth, free from contaminating 

 influences. From this field heads of grain were picked with steri- 

 lized forceps and put into sterilized glass tubes. These heads were 

 incubated separately in broth for 24 hours, and then cultures on 

 litmus lactose agar were prepared, following the usual procedure. 

 On December 10 and January 17 two more lots of grain heads were 

 treated in similar manner. In all, 34 heads from this field of rye 

 were studied, and from six of them organisms were isolated giving 

 the reactions of the colon bacillus on all ordinary media and with 

 neutral red lactose broth. It will be recalled that these heads were 

 taken at random over the whole field after they had stood through 

 the storms of the fall and snows of the early winter. Other heads 

 of rye gave acid-producing organisms, but not those exhibiting the 

 typical colon reactions in all respects. 



The occurrence of acid- and gas-producing organisms under these 

 conditions has been known for several years, as it was shown by 

 Underwood and one of us 25 in 1897, an d again in 1898, that acid- 

 producing organisms of numerous types are of common occurrence 

 upon the ears of sweet corn beneath the husks, and upon the surfaces 

 of peas in the pod, with practically complete protection from con- 

 tamination from the external world. 



Although in the investigations cited only the resistant types of 

 organisms were thoroughly studied, the more recent work shows 

 the strong probability that organisms of the colon and Strept. pyogenes 

 types were likewise present. Further evidence on this point is afforded 

 by some experiments begun by us in Wisconsin, in which we exam- 

 ined a large number of kernels of corn from ears carefully selected 

 in the field because of their isolation from polluting substances and 

 further protection from closely packed husks. Although the experi- 

 ments were not carried out in the great detail of those previously 

 described, the presumptive tests first employed gave strong evidence 

 of the abundance of these bacteria on the grain. 



