In Romanowsky-stained preparations we see, while the fever is sustained, small hair-like rings, with geometrical outline, with frequently two chromatin dots in one end of the ring and a single red cell often showing two or more of these young rings. The rings are often seen as if plastered on the periphery of the red cells or as if having destroyed a rounded section of the rim of the red cell. As the fever declines the rings tend to disappear from the peripheral circulation. The infected red cells often show polychromatophilia and distortion. [Illustration: FIG. 8.—Tertian malarial parasite, one red cell showing malarial stippling. (Todd.) FIG. 9.—Estivo-autumnal malarial parasites, and small ring forms and crescents. (Todd.)] In old aestivo-autumnal cases, or those with severe infection, we may see adult rings and merocytes, which latter are smaller than those of benign tertian, show from 10 to 12 irregularly placed merozoites and a sharply clumped mass of pigment. The gametes are the striking crescent-shaped bodies and these show the distinctions of blue-staining for the female, with lighter gray-blue to purplish staining and abundance of chromatin for the male. The chromatin staining of crescents does not stand out so well as that of the round form gametes of benign tertian and quartan. The black pigment of the female tends to be clumped toward the center while the rather generally distributed pigment of the male is reddish brown rather than black in a stained preparation. This variation of pigment color may be due to the effect of chromatin staining, as the black of the pigment is the same in male and female gametes in fresh blood preparations. _Stained Smear Preferred._—As regards differentiation of species and cycle the examination of stained smears is more satisfactory and definite, as well as less time consuming. Still, one obtains many points of differentiation in the fresh preparation and should study such a preparation while carrying out the staining of his dried smear.