130 A MANUAL OF BACTERIOLOGY 



vations for an hour to a temperature of 46 C., the 

 virulence of this microbe is greatly reduced ; and in 

 this attenuated or weakened form it has been used 

 for the protective inoculation of sheep and cattle. 



Micrococcus of foot-and-mouth disease. According 

 to Dr. Klein, the microbe of this disease occurs 

 singly, as diplococci, and in curved chains. ' It 

 grows well in milk, in alkaline peptone broth, in 

 nutrient gelatine, and in agar-agar mixture. Grow- 

 ing on solid material, its growth, besides being 

 extremely slow, is very characteristic; it forms a 

 film composed of minute granules or droplets, 

 closely placed side by side, but not confluent. It 

 does not liquefy nutrient gelatine, and in liquids 

 does not form a pellicle, but nevertheless when 

 grown on solids, its growth remains limited to the 

 surface. It does not curdle milk, although it turns 

 the reaction of this latter slightly but distinctly 

 acid.' The microbe has been observed in the vesicles 

 of sheep suffering from the disease. 



Micrococcus septicus. The cells are 0*5 //, in dia- 

 meter, and occur singly, as diplococci and chains. 

 Colonies are produced very slowly on nutrient 

 gelatine; they are seen as minute dots on the 

 fourth and fifth days in plate and tube cultivations. 

 They are fatal to mice, rabbits, etc. ; the vessels in 

 the various organs become plugged with these 

 microbes, this ultimately forming purulent or 

 necrotic foci. M. septicus is present in soil. 



Micrococcus in gangrene. Small oval micrococci 

 have been found in gangrene of the lungs. They 

 live in colonies, form zoogloaa, and grow on nutrient 



