220 
PHARMACEUTICAL BOTANY 
hold eight billion of them—the student commences his study of 
bacterial growths in colonies or cultures, each kind possessing 
characteristics by which they may be distinguished and differentiated. 
The individuals in the colony, depending upon the kind of bac¬ 
teria under examination, may be globular, rod-shaped, or spiral. 
Bacteria are classed according to form into the following families 
and genera. 
Fig. 106.—Types of micrococci. ( After Williams.) 
Family I.—Coccaceae. —Cells in their free condition globular, be¬ 
coming but slightly elongated before division. Cell-division in one, 
two or three directions of space. 
A. Cells without Flagella. 
1. Division only in one direction of space forming an aggregation 
resembling a chain of beads—Streptococcus. 
2. Division in two directions of space forming an aggregation 
resembling a cluster of grapes—Staphylococcus. 
Fig. 107.—Types of bacilli. ( After Williams.) 
3. Division in three directions of space forming a package-shaped 
or cubical aggregation—Sarcina. 
B. Cells with Flagella. 
1. Division in two directions of space—Planococcus. 
2. Division in three directions of space—Planosarcina. 
Family II.—Bacteriaceae. —Cells longer than broad, generally two 
to six times, straight or only with an angular bend, never curved or 
spiral, division only at right angles to axis or rod; with or without 
flagella and endospores. 
1. Flagella and endospores absent—Bacterium. 
