293 BACILLI PATHOGENIC IN MAN. 



necrosis of the epithelium of the cornea, and to suppura- 

 tive inflammation of the cornea. According to Kusch- 

 bert and Neisser, the bacilli are about as long as thoso 

 of mouse septicaemia, and are of varying breadth, accord- 

 ing as the sheath which surrounds the bacillus like a 

 capsule is stained or unstained. If a small portion of 

 the deposit on the surface of the conjunctiva is stroked 

 over the surface of blood serum jelly, dry, fatty whitish 

 streaks grow, at the temperature of 87 C., these streaks 

 consisting of bacilli similar to those found on the con- 

 junctiva. Neisser observed the production of spores, 

 forming small spherical swellings at each end of the 

 bacillus. At times the terminal joints break up into 

 broad plates, or become swollen like a pear (formation 

 of involution forms). Experiments on animals with the 

 cultivations gave entirely negative results. As, how- 

 ever, the methods of cultivation employed were not 

 devised with sufficient care to exclude accidental bacteria, 

 which were so apt to be present on account of the exposed 

 seat of the disease, the question as to the significance 

 of the bacteria, which have as yet been found, for the 

 etiology of xerosis cannot be regarded as completely 

 settled. 



In the case of canes of the teeth, which is probably 

 due to the action of one or several species of specific 

 bacteria, different bacilli have been isolated, which, how- 

 ever, seem chiefly to play a saprophytic part, and at the 

 most to prepare the tooth for the occurrence of caries. 

 As regards these organisms, see below. 



As regards leptothrix and other bacteria of the mouth, 

 see later. As regards jeqnirity, see the following 

 chapter. 



