Bacterial Tenants of the Human Body 69 



who isolated twenty-nine forms from the skin of the foot; and Prein- 

 delsberger,* who found eighty species of bacteria on the hands. 

 Undoubtedly many of these organisms were accidentally present, and 

 were at least only semi-parasitic. Not a few were met but once 

 and were in no sense bacteria of the skin. The skin may also be 

 temporarily contaminated with bacteria from other portions of the 

 patient's body, as, for instance, from his intestine; thus Winslowf 

 has found the colon bacillus upon the hands of ten out of one hundred 

 and eleven persons examined. Wiguraf also examined the hands 

 of forty persons in hospitals, finding tubercle bacilli in two out of 

 ten persons from phthisical wards, colon bacilli six times and typhoid 

 bacilli once on the hands of nine attendants in the typhoid wards. 

 He found streptococci and staphylococci many times. Welch and 

 Robb and Ghriskey|| seem to have been the first to make a clear 

 differentiation between the accidentally present bacteria and the 

 permanently parasitic organisms of the skin, and to show that cer- 

 tain cocci, producing white and yellow colonies upon agar-agar, 

 were invariable in occurrence and penetrated to the lowest epidermal 

 layers. 



These cocci, of which . Welch describes the most common as 

 Staphylococcus epidermidis albus, are universally and invariably 

 present upon the human skin, and must be regarded 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 invariable, and the recent work by Schaudinn 

 and Hoffmann** 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, ft 

 who found six organisms Leptothrix innominata, Bacillus buccalis 



* "Samml. medic. Schriften," herausg. von der "Wiener klin. Wochenschrift," 

 1891; xxn, Wien, "Rev. Jahresbericht uber die Fortschritten in der Lehre von 

 den pathogenen Mikroorganismen," 1891, vn, p. 619. 



"Jour. Med. Research," vol. x, p. 463. 

 f"Wratsch," 1895, No. 14. 



"Transactions of the Congress of American Physicians and Surgeons," 

 , H, p. i. 



"Bulletin of the Johns Hopkins Hospital," 1892, in, p. 37- 

 '* "Deutsche med. Woch.," May 5, 1905. 

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



