3. Miscellaneous contaminations: Some investigators, especially certain German writers, regard the bacilli of the paratyphoid group as so widely distributed in nature that any attempt to control the spread of infection is like fighting windmills. According to this view the bacilli occur commonly in our everyday surroundings and thence make their way rather frequently into a variety of foodstuffs. Various German investigators have reported the presence of paratyphoid bacilli in the intestinal contents of apparently normal swine, cattle, rats, and mice and more rarely of other animals, in water and ice, in German sausage and chopped meat, and in the bodies of apparently healthy men. To what extent their alleged ubiquity is due to mistaken bacterial identification, as claimed by some English investigators, remains to be proved. There is no doubt that in some quarters exaggerated notions have prevailed respecting a wide distribution of the true paratyphoid bacteria. Savage and others believe that the hypothesis that food poisoning outbreaks are derived from ordinary fecal infection of food is quite unfounded. It is pointed out that there is good evidence of the frequent occurrence of intestinal bacteria in such food as sausages and chopped meat, and that consequently, if paratyphoid infections could occur through ordinary contamination with intestinal bacteria not connected with any specific animal infection, food poisoning outbreaks should be exceedingly common instead of--as is the case--comparatively rare. At the present time even those who maintain that these bacilli are of common occurrence admit that their abundance is more marked in some regions than in others. Southwest Germany, for example, seems to harbor paratyphoid bacilli in relatively large numbers. Possibly local differences in distribution may account for the discrepancies in the published findings of German and British investigators. A special case is presented by the relation of these bacilli to rats and mice. Among the large number of bacteria of the paratyphoid group is the so-called Danysz bacillus, an organism quite pathogenic for rodents, and now and again used in various forms as a "rat virus" for purposes of rodent extermination. Several outbreaks of food poisoning in man have been attributed on more or less cogent evidence to food contamination by one of these viruses either directly by accident, as in the case described by Shibayama,[87] in which cakes prepared for rats were eaten by men, or indirectly through food contaminated by mice or rats that had been infected with the virus.[88] The use of such viruses has not proved of very great practical value in the destruction of rodents, and is open to serious sanitary objections, since the animals after apparent recovery can continue to carry the bacilli of the virus and to distribute them on or near food substances.