PLATE XXV. 



FIG. i. BACILLUS PNEUMONI/E (FRIEDLANDER). 



From a streak culture i>n agar, of twenty- four ho\\rs' growth, incubated at 37C. 



Stained wii h aqueous solution of gentian violet, washed in caustic potash solution i part 

 to '0,000), followed by tap-water. 



Thick rods of varying length, the shortest appearing as ovals or even as coccus fornih or 

 spheres. Fairs of oval (or spherical) elements, end-to-end nre not uncommon. In some <( 

 the shelter form-; one or more circular vacuoles are present. 



In pure cultures the micro-organism has no capsule such as it presents when found in the 

 sputum or lung in acute pneumonia 



It is not stained by Grain's method, and in this contrasts with the diplococcus pneumoni.c 

 which is found in othi-r cises of acute pneumonia, in the sputum and pulmonary tissue, etc. 



FIG. 2. 

 SPIRILLUM OF ASIATIC CHOLERA (KOCH'S "COMMA BACILLUS "V 



From a streak culture on agar, of twenty-four hours' growth, incubated at 37 C. 



Aqueous solution of gentian violet, washed in i in 10,000 caustic potash solution, followed 

 t>y tap-water. 



A group of typical, slighty-cur\ed rods is shown at the lowest part of the figure ', others 

 are selected to show varieties of form. The rods vary in length as well as in thickness. 

 Some are sharply curved like the letter C ; others are curved in opposite directions and 

 present two bends like a shallow S. 



Some of the bacilli exhibit one or two circular vacuoles ; the vacuole may occupy one end 

 of the rod, which may be slightly enlarged. Although commonly rounded, the extremities of 

 the bacilli may be bluntly pointed. In addition to the simple, curved rods, there are longer 

 filamentous, undulatory forms of different lengths; these present no traces of a segmented 

 or composite structure. The proper spirillar or twisted feature of the filamentous forms is 

 appreciable only in a hanging drop made, e.g., from a broth culture. In such a drop even 

 the longest forms are twisted, as appears by the alternation of parts within and out of focu. 

 In 'iried preparations the curves are reduced to a single plane, the filament becoming 

 undulatory or serpentine without spiral twist. 



