GENERAL SYSTEMATIC BACTERIOLOGY 93 



b. Not in zoogloea masses : 



1. Pairs or chains encapsulated, soluble in bile and salt solu- 



tions Diplococcus 



2. Chains, not encapsulated, not soluble in bile or salt solutions. 



Streptococcus 

 II. Pigment present : 



a. Orange, Aurococcus 



h. White, Albococcus 



Key to the Genera of the Tribe Micrococceae 



A. Pigment red Rhodococcus 



B. Pigment yellow: 



I. Cells in irregular groups Micrococcus 



II. Cells in packets Sarcina 



C. Pigment black Nigrococcus 



Key to the Tribe of the Family Bacillaceae 



Growth in ordinary laboratory media: 



A. Entirely or almost entirely absent. 



Tribe 1. Nitrobactereae 



B. Poor, Gram-negative, grow best on blood media. 



Tribe 2. Haemophileae 



C. Extremely slow and scanty growth on ordinary and blood media. 



Tribe 3. Graciloideae 



D. Growth good: 



I. Endospores present Tribe 4. Bacilleae 



II. Endospores absent: 



(a) Fluorescent or chromogenic. 



Tribe 5. Bacteridieae 



(b) Neither fluorescent nor chromogenic : 



1. Obligatory anaerobes Tribe 6. Bacteroideae 



2. Aerobes often facultative anaerobes: 



(1) Gelatine liquefiers. 



Tribe 7. Proteae 



(2) Gelatine non-liquefiers : 



(i) Without capsules: 



(A) With polar staining. 



Tribe 8. Pasteurelleae 



(B) Without polar staining. 



Tribe 9. Ebertheae 

 (ii) With capsules. 



Tribe 10. Encapsulateae 



Key to the Tribe Encapsulateae 



This tribe contains one genus only Encapsulateae 



Key to the Genera of the Tribe Ebertheae 



A. Glucose and lactose either not at all or only partially fermented with the 

 production of acid, but no gas : 



