80 MORPHOLOGY OF THE BACTERIA. 
Rhabdomonas rosea, Cohn. 
Cells pale pink, isolated, fusiform ; eight times as 
long as broad, having a length of 20 to 30 w, anda 
width of 3.8 to 5 w; having a slow oscillatory move- 
ment, the pink substance containing numerous gran- 
ules of darker color and vacuoles. Hab., stagnant 
water. 
Ophidomonas sanguinea, Ehrb. 
Cells pale pink, spiral, rigid, movement active ; 
thickness 3 yp, length of one turn of the spiral, 9 to 
12 4. Hab., brackenish waters of Denmark (Warm- 
ing). 
Spiromonas Cohni, Warming. 
Cells spiral, flattened; 14 turn of spiral, diam. 1.2 
to 8.5 w, width 1.2 to 4 ». Hab., coast of Denmark. 
9. MICROBACTERIA, Cohn. 
Rod-bacteria, cells cylindrical, short, having spon- 
taneous movement. 
A single genus, — Bacterium. 
g. Bacterium, Duj. emend. 
Cells cylindrical or elliptical, free or united 
in pairs during their division, rarely in fours, 
never in chains (leptothrix or torula), sometimes 
in zooglea (differing from the Z. of spherical B. 
by a more abundant and firmer intercellular 
substance), having spontaneous movements, os- 
cillatory and very active, especially in media 
rich in alimentary material and in presence of 
oxygen. 
