TROPHOZOITE
SIZE: 40 to 50 by 50 to 70 mcm.
SHAPE: Sac-like.
NUCLEUS: Macronucleus: large, enlongate, kidney-shape (mitotic division);
micronucleus: small, spherical (amitotic).
CYTOPLASM: Cell membrane covered with a delicate pellicle.
CILIA: Locomotion and food procurement; fine hair-like projections.
GULLET: Cytostome; anterior end: funnel shape peristome; posterior end:
rounded, peristome.
CYTOPYGE: Excretory pore, posterior.
PULSATING VACUOLES: One or two.
CYST
SIZE: 30 by 55 mcm.
SHAPE: Oval to round.
NUCLEUS: Only the macronucleus is seen.
CYTOPLASM: Double cyst wall; remnants of cilia and gullet.
Figure 2-3. Stages of B. coli.
MD0842
2-4