IMPRESSION OR ADHESIVE PREPARATIONS. 75 
Nacreous, translucent, grayish white with 
pearly luster. 
Sebaceous, translucent, yellowish or gray- 
ish white. 
Butyrous, translucent and yellow. 
Ceraceous, translucent and wax-colored. 
Opaque. 
Cretaceous, opaque and white ; chalky. 
Dull, without luster. 
Glistening. 
Fluorescent. 
Tridescent. 
Phosphorescent. 
(d) Is there growth beneath the cover-glass or 
mica plate? ‘This determines, roughly, whether 
they require oxygen for their growth or not (aérobic 
or ana€érobic). 
(e) In the gelatin plates is the gelatin liquefied, 
and what is the nature of the liquefaction ? 
V. IMPRESSION OR ADHESIVE PREPARATIONS OF 
COLONIES. 
An entire colony of bacteria may be preserved as 
a microscopic specimen. 
(a) Slightly warm a clean cover-glass. 
(6) Lay it upon the surface of the gelatin or agar 
containing the colonies. Apply sufficient pressure 
to remove all air-bubbles, but not enough to disturb 
the colony. 
(c) Remove the cover, gently lifting it from one 
side. ‘The colonies will adhere to the glass. 
