THE DISTRIBUTION OF MICRO-ORGANISMS 193 



is chilled in cool water, then ice water, and finally stored in the 

 refrigerator. Immediately before feeding it is warmed by partial 

 immersion in warm water. 



Other Foods. Other foods, meats, fish, eggs, vegetables 

 and fruits, undergo decompositions due to more or less definite 

 types of micro-organisms, and the activities of these are delayed 

 or prevented by modern methods of preserving foods, in some 

 instances very successfully, and in other cases with limited success. 1 

 Any food, and especially that eaten without cooking, may serve 

 as a passive carrier of pathogenic micro-organisms. Salads, 

 green vegetables and fresh fruits may undoubtedly act in this 

 way during epidemics. Oysters taken from sewage-polluted 

 beds have been found to convey typhoid fever. Meats derived 

 from mammals may contain specific germs causing disease in 

 both animals and man, such as tuberculosis, anthrax and foot-and- 

 mouth disease. The flesh of bovine animals suffering with 

 enteritis at the time of slaughter seems to be particularly liable 

 to develop poisonous properties, and the ill effects observed in 

 these instances may have been due to a specific infection. Para- 

 typhoid fever is sometimes traced to such meat as a cause. 



Meats and fish are rich in protein and their decomposition 

 by saprophytic bacteria may give rise to various poisonous sub- 

 stances, as has been mentioned on page 170. The usual course 

 of putrefaction, however, goes on without very strong poisons 

 being produced, as we may judge from the habitual use of partly 

 decomposed foods of this sort. Virulent poisons are occasion- 

 ally encountered and some of these are due to the presence of 

 specific microbes, B. botulinus of Van Ermengen, B. enteritidis of 

 Gaertner and the paratyphoid and paracolon bacilli. 2 



1 For a discussion of the microbiology of foods and of food preservation see 

 MarchalFs Microbiology for agricultural and domestic science students, 1911. 



2 Consult Bolduan, C. F.: Bacterial Food Poisoning, N. Y. 1909. Also Novy, 

 F. G.: Food Poisons, Osier's Modern Medicine, Vol. I, Phila., 1907. 



