224 BACTERIOLOGY. 



fresh alcohol, treated with clove-oil, and preserved in 

 Canada balsam. 



Sections containing cocci of osteomyelitis may be after- 

 stained with weak solution ofvesuvin. Safranine and picro- 

 lithium-carmine may also be used as contrast stains (p. 61). 



Nuclear stains, such as carmine, hsematoxylin, may also 

 be employed. Sections may be left one minute in 

 Grenacher's solution, then washed out in weakly acidulated 

 alcohol (2 1000) ; and finally treated in the usual way, 

 with alcohol, oil of cloves, and balsam. 



Sections containing micrococciis tetragonus are best 

 stained with Gram's method and eosin (Plate XII., Fig. i), 

 but they may also be treated by the method of Fried- 

 lander, to demonstrate their capsules (p. 227). 



To stain the cocci of rabbit- septic&mia in the tissues, 

 place the sections twenty-four hours in Loffler's solution, 

 wash in water faintly acidulated with acetic acid, then treat 

 with alcohol, oil of cloves, and balsam. 



GROUP II. BACTERIACE^:. 



Genus I. Bacterium. Cocci and rods, or only rods, 

 which are joined together to form threads. Spore- 

 formation absent or unknown. 



Genus II. Spirillum. Threads screw-form, made up 

 of rods (long or short) only, or of rods and cocci. 

 Spore-formation absent or unknown. 



Genus III. Leuconostoc. Cocci and rods. Spore- 

 formation present in cocci. 



Genus IV. Bacillus. Cocci and rods, or rods only, 

 forming straight or twisted threads. Spore- 

 formation present either in rods or cocci. 



Genus V. Vibrio. Threads screw-form in long or 

 short links. Spore-formation present. 



Genus VI. Clostridium. Same as bacillus, but spore- 

 formation takes place in characteristically en- 

 larged rods. 



