Giardia lamblia

Giardia lamblia and Chilomastix mesnili. Cysts in fecal smear (trichrome stain, oil immersion). Mature cysts of these two species are distinctly different in size and morphology. A typical smaller uninucleate cyst of Chilomastix is seen adjacent to a larger mature cyst of Giardia in which only two of the characteristic four nuclei are visible.