364 .4 CTER10LOGY. 



BACTERIUM LEPR^E. Between 1879 and 1881 there 

 was described by Hansen and by Neisser an organism, 

 a bacillus, that was constantly to be found in the nodules, 

 characteristic of leprosy. For this organism the name ba- 

 cillus leprce was suggested. Though very like bacterium 

 tuberculosis in both morphology and staining properties, 

 it is, however, a little shorter, thicker, and muc!* less 

 homogeneously stained. Its presence in the tissues and 

 secretions is demonstrated by the same method as that 

 employed for detecting bacillus tuberculosis. In sec- 

 tions of leprous nodules, stained by the ordinary Koch- 

 Khrlich process, the bacilli, crowded together in the 

 large so-called " lepra cells/ 7 are always to be seen in 

 great abundance. It is unlikely that bacillus leprse has 

 ever been cultivated artificially, and the disease has cer- 

 tainly never been reproduced in animals by inoculation 

 with bits of the diseased tissue, so that nothing can be 

 said of the life-history of this organism. 



BACTERIUM SMEGMATIS. In 1885 Alvarez and 

 Tavel discovered in the fatty secretions about the gen- 

 italia an organism that suggested the bacterium of 

 tuberculosis. It was found both in syphilitic and in 

 healthy persons. Their observation has been abundantly 

 confirmed by others, and the organism to which they 

 directed attention is now regarded as pretty commonly 

 present in the smegma. It is known, therefore, as the 

 smegma bacterium (bacterium smegmatis). In this 

 secretion it is found in clumps located upon or within 

 epithelial cells. It stains by the method used in staining 

 bacterium tuberculosis. It has no pathogenic power. 

 It is said to have been artificially cultivated upon coag- 

 ulated hydrocele fluid and in milk. 



In 1884 Lustgarten described an organism, the so- 



