268 METHODS OF IDENTIFICATION AND STUDY 



Vitreous : Transparent and colourless. 



Oleaginous: Transparent and yellow; olive to lin- 

 seed-oil coloured. 



Resinous : Transparent and brown, varnish or resin- 

 coloured. 



Translucent : Faintly transparent. 



Porcelaneous : Translucent and white. 



Opalescent: Translucent; greyish- white by reflected 

 light. 



Nacreous: Translucent, greyish- white, with pearly 

 lustre. 



Sebaceous: Translucent, yellowish or greyish- white. 



Butyrous : Translucent and yellow. 



Ceraceous: Translucent and wax-coloured. 



Opaque. 



Cretaceous : Opaque and white, chalky. 



Dull : Without lustre. 



Glistening: Shining. 



Fluorescent. 



Iridescent. 



2. Chroma genicity: 



Colour of pigment. 



Pigment restricted to colonies. 



Pigment restricted to medium surrounding colonies. 



Pigment present in colonies and in medium. 



Streak or Smear Cultures. 



Gelatine and Agar. Note general points as indicated 

 tinder plate cultivations. 



Inspissated Blood-serum. Note the presence or 

 absence of liquefaction of the medium. (The presence 

 of condensation water at the bottom of the tube must 

 not be confounded with liquefaction of the medium.) 



All Oblique Tube Cultures. 



i. Colonies Discrete: Size, shape, etc., as for plate 

 cultivations (vide page 261). 



