MYCOBACTERIUM LEPRAE. 423 



that the separation of leprous and tuberculous affections 

 in the cadaver appears often impossible, since at least it is 

 made differently by different persons. Since, according to 

 Hansen and Looft (Bibl. med., 1894), the cause of death 



I in 40% of the cases of leprosy is tuberculosis, this uncer- 

 tainty is very unfortunate. 

 While for a long time efforts to obtain cultures of the 

 infective agent from cases of leprosy were frustrated, more 

 recently positive results have multiplied. 

 Almost all the cultures obtained present branched forms 

 closely related to the Myc. tuberculosis ; the typical acid- 

 resisting power was rarely present (Bordoni-Uffreduzzi, Z. 

 H. in, 178, with plate); sometimes there was a certain 

 limited acid-proof property, and at other times none at 

 all. Babes, who, if not the first to study this subject, has 

 studied it most extensively, holds the organism, for evi- 

 dent reasons, to be the cause of lepra in spite of the absence 

 of acid-proof quality (C. B. xxv, 125). 



The growth upon artificial nutrient media (glycerin- 

 agar, glycerin-serum-agar, glycerin-potato) was found by 

 all writers to usually be delicate and slow; morphologically 

 and biologically their behavior was very similar to the 

 T. B. Our culture obtained from Krai exhibited a good, 

 although a slow, growth. Morphologically the rods re- 

 semble the T. B. , but also the diphtheria bacterium. * 



An additional proof that we may recognize the culti- 

 vated organisms with the greatest probability as the Myco- 

 bacterium lepras has been furnished by Spronck (C. B. 

 xxv, 257). It is the demonstration of agglutination of 

 the questionable organisms by serum from many cases of 

 lepra, even in high dilution. 



Animal experiments are said by some authors to have 

 succeeded (see Wolters), but no one has produced typical 

 leprous changes. The greatest number of writers observed 



1 Czaplewski (C. B. xxiii, 97), who has also isolated an organism 

 belonging here, says with entire truth that these forms constitute a 

 connection between the diphtheria and tuberculosis groups, or, accord- 

 ing to our terminology, the genus Mycobacterium and the genus 

 Corynebacterium, which, in the first edition of this book, we placed 

 side by side as closely related. See also Levy (A. H. XXX, 168). 



