Micro-Organismal Tenants of the Normal Human Body 75 



curved, are attenuated at the ends and when typical are Gram- 

 negative and stain uniformly. Sometimes they show a Gram- 

 positive granule, sometimes a punctate appearance and may 

 resemble a chain of cocci. This organism first described by Escherich 

 and later isolated and cultivated by Tissier is Bacillus bifidus. 

 It is an obligatory anaerobe, capable of fermenting lactose and other 

 sugars with the production of considerable acid, but no gas. In 

 culture it shows a peculiarity not shared by other known bacilli, 

 namely, a bifid or divided appearance of its ends. BaciUus acido- 

 philus. Micrococcus ovalis. Bacillus coli, Bacillus lactis aerogenes 

 and other bacteria are also found. 



In adult life the acidity of the gastric contents, that continues into 

 the duodenum, and the more rapid passage of food through the upper 

 as contrasted with the lower bowel, determines that the bacteria 

 shall increase in number as the ileocecal region is approached. 

 Staphylococci and streptococci may occur high up, with a few Gram- 

 positive bacilli; lower down Gram-negative bacilli of the B. coli group 

 and some of the B. proteus group are the chief organisms. About 75 

 per cent, of the bacteria of the normal adult feces are B. coli, and 

 of those in the colon about 90 per cent, are dead or incapable of 

 growing in artificial media. 



The total bacteria that finally appear in the feces, according to the 

 studies of Strasburger* and Steele,t may reach the enormous figure 

 of 38 per cent, of the total bulk. 



MacNeal, Latzer, and Kerr,t in an elaborate work upon the 

 "Fecal Bacteria of Healthy Men," found that they furnished 46.3 

 per cent, of the total fecal nitrogen. 



Rettger§ found the Bacillus enteritidis sporogenes regularly pres- 

 ent in the human feces and believes it to be responsible for some of 

 the putrefactive processes that occur there. Yeasts of various kinds 

 are commonly present in the intestinal contents and have been care- 

 fully studied by Anderson. || Molds also occur occasionally. Amoeba 

 are not infrequent in occurrence, and flagellate and ciliate pro- 

 tozoan organisms sometimes occur in considerable numbers in the 

 intestinal contents of apparently normal human beings. 



The vagina, on account of its acid secretions, harbors but few 

 bacteria. In a study of the vaginal secretions of 40 pregnant women 

 who had not been subjected to digital examinations, douches, 

 or baths, Bergholm** found but few organisms of limited variety. 

 A flagellate organism. Trichomonas vaginalis is somtimes found in 

 the vaginae of apparently healthy women. 



The uterus harbors no bacteria in health, and but few in disease. 



* "Zeitschrift fur klin. Med.," 1902, XLiv, 5 and 6; 1903, XLViii, s and 6. 

 t "Jour. Amer. Med. Assoc," Aug. 24, 1907, p. 647. 

 t "Journal of Infectious Diseases," 1909, vi, pp. 132, 571. 

 § "Jour, of Biological Chemistry," Aug., 1906, n, i and 2, p. 71. 

 1] "Journal of Infectious Diseases," 191 7, xxi, No. 4, p. 341. 

 ♦■^ "Archiv f. Gynak.," Bd. ixiv, Heft 3. 



