BACILLI IN CHRONIC INFECTIOUS DISEASES. 415 



bent or curved. The rods have pointed ends ; and in stained pre- 

 parations unstained spaces, similar to those observed in the tubercle 

 bacillus and generally assumed to be spores, are to be seen, although 

 not quite so distinctly as in the latter. The bacilli are said by Fliigge 

 to be from four to six /* in length and less than one /* in width 

 probably considerably less, for the same author states that the tubercle 

 bacillus has about the diameter of the bacillus of mouse septicaemia, 

 and this is given as 0.2 P-. 



This bacillus stains readily with the aniline colors and also 

 by Gram's method. Although it differs from the tubercle bacillus 

 in the ease with which it takes up the ordinary aniline colors, it re- 

 sembles it in retaining its color when subsequently treated with 

 strong solutions of the mineral acids. Double-stained prepara- 

 tions are therefore easily made by first staining sections or cover- 

 glass preparations in Ziehl's carbol-f uchsin solution or in an aqueous 

 solution of methyl violet, decolorizing in acid, washing in alcohol, 

 and counter-staining with methylene blue or, if methyl violet was 

 used in the first instance, with vesuvin. 



Biological Characters. The earlier attempts to cultivate this 

 bacillus were without success, but recently Bordoni-Uffreduzzi has 

 obtained from the marrow of the bones of a leper a bacillus which 

 he believes to be the leprosy bacillus, and which he was able to culti- 

 vate upon blood serum to which a certain amount of peptone and of 

 glycerin had been added. At first this bacillus only grew with diffi- 

 culty and in the incubating oven ; but after it had been cultivated 

 artificially through a number of generations it is said to have grown 

 upon ordinary nutrient gelatin at the room temperature. The bacillus 

 obtained in this way is said to have retained its color when treated 

 with acids, after having been stained with aniline-f uchsin, correspond- 

 ing in this respect with the bacillus of leprosy and the tubercle ba- 

 cillus. But it differed considerably in its morphology from the Ba- 

 cillus leprsBas seen in the tissues of lepers, being considerably thicker, 

 and it was not so promptly stained by the aniline colors as is the 

 bacillus found in the tissues. Moreover, attempts to cultivate the 

 same bacillus from leprous tubercles of the skin were unsuccessful, 

 as were also inoculation experiments into the anterior chamber of the 

 eye in rabbits. It is therefore a matter of doubt as to whether the 

 bacillus obtained by Bordoni-Uffreduzzi is identical with that present 

 in such numbers in the cells of the leprous tubercles, to which the 

 name Bacillus leprse has been given. 



Some of the earlier observers described the bacillus of leprosy as 

 motile, but this assertion seems to have been based upon some error 

 of observation, and it is now generally agreed that, like the tubercle 

 bacillus, it is without proper movements. The question of spore for- 



