Bacteria of the Digestive Apparatus 63 



as Staphylococcus epidermidis albus, are universally and 

 invariably present upon the human skin, and must be re- 

 garded as habitual parasites. 



Where the skin is peculiar in its moisture and greasiness, 

 however, additional forms are found. Thus, in preputial 

 smegma, in the axillae, and sometimes about the lips and 

 nostrils, a bacillary organism, Bacillus smegmatis, is invari- 

 able, and the recent work by Schaudinn and Hoffman* has 

 shown that the skin of the genitalia harbors a spiral organism 

 which they call Spirochaeta refringens. 



In the ' external auditory meatus a coccus, Micrococcus 

 cereus flavus, is almost always to be found in the waxy 

 secretion. 



Upon the conjunctiva as many accidental organisms may 

 be found as shall have been caught by its moist surface, 

 though the researches of Hildebrand and Bernheim and 

 others seem to show that the tears have some antiseptic 

 power and prevent the organisms from growing, so that in 

 health there are very few permanent residents of the sac, 

 certain cocci seeming to be the only constant forms. 



The mouth has been carefully studied bacteriologically 

 by Miller, f who found six organisms Leptothrix innomi- 

 nata, Bacillus buccalis maximus, Leptothrix buccalis 

 maxima, lodococcus vaginatus, Spirillum sputigenum and 

 Spirochaeta dentinum (denticola) in every mouth. These 

 organisms are peculiar in that they will not grow in arti- 

 ficial culture. In addition to this permanent flora, Miller 

 cultivated fifty-two other species, some of which were harm- 

 less, some well-known pathogens. From the mouth these 

 organisms may be traced into the pharynx and esophagus. 



The stomach seems to retain very few of the many 

 bacteria that must enter it, its persistently acid contents 

 being inimical to their development. Certain sarcina, 

 especially Sarcina ventriculi, may be found without any 

 considerable departure from the normal state. In carcinoma 

 and other forms of pyloric obstruction with dilatation, the 

 bacterial flora increases, and in achlorhydria micro-organ- 

 isms of fermentation Bacillus acidi lactici and Bacillus 

 butyricus make their appearance. They are, however, 

 accidental and not permanent tenants of the organ. 



The intestine receives such micro-organisms as have 



* " Deutsche med. Woch.," May 4, 1905. 



f " Micro-organisms of the Human Mouth," Phila., 1890. 



