THE BIOLOGY OF MICROBES, ETC. 163 



plates, it produces 'dot-like colonies, and in test- 

 tubes little spherical masses in the needle track, and 

 a layer on the free surface/ This bacillus was 

 isolated by Koch from putrid meat infusion and 

 river-water. It is innocuous to guinea-pigs and 

 white rats ; but rabbits, mice, and birds are very 

 susceptible to the attacks of this microbe. 



Bacillus septiccemice (mouse). This non-motile 

 bacillus was isolated from garden soil and putrefy- 

 ing fluids. It measures 1 x O'l /*, and occurs 

 singly, in pairs, and chains of four or more. It 

 grows on gelatine-plates, in the deeper layers of the 

 medium, as delicate white clouds. In test-tube 

 cultivations, it produces delicate branching growths 

 along the track of the needle. On agar-agar, lemon- 

 yellow colonies are formed. This bacillus kills 

 house-mice in forty to sixty hours; but field-mice 

 have an immunity. 



Bacillus septiccemice (man). In human septicaemia, 

 Klein x found in the blood-vessels of the lymphatic 

 glands certain bacilli which form continuous masses 

 in the capillaries and small veins. These bacilli 

 measure 1 to 2*5 //, x 0*3 to 0*5 JJL, and occur singly 

 or in short chains. 



Bacillus diphtlierice vitulorum. This microbe 

 measures 2 -5 to 3' 6 x 0*5 /&, and was described by 

 Loffler as occurring in the diphtheria of calves. 

 Mice inoculated from a calf died with all the 

 characteristic symptoms of the disease. The 

 microbe has not been artificially cultivated. 



Bacillus diphtheria columbarum. This bacillus 



1 Micro-Organisms and Disease, p. 120 (3d ed.). 



