The Extracellular Relation of the Malarial Parasite to the Red Corpuscle, and Its Method of Securing Attachment to the External Surface of the Red Corpuscle

Laveran ( I ) has consistently claimed f rom the beginning that the parasites were extracellular and that they attached themselves to the surface of the red corpuscles, adhering to them " b y pressing on them." Richard (2) thought at one time that the parasites were within the substance of the red corpuscle; but later (3) he returned to Laveran 's opinion that they were attached to the surface. Mannaberg (4) inclines to the opinion that the young unpigmented parasites " l i e for a considerable t ime upon the blood corpuscles . . . . In the places where the parasites were observed, distinct impressions in the substance of the blood corpuscles are noticed, and that the margin of the so-formed depression is perfectly sharp . . . . I f these bodies were within the substance of the blood corpuscle, one cannot unders tand how the observed depression in the upper surface or edge of the blood corpuscle takes place." Marchiafava and Bignami (5) describe a similar condition, depicting the parasites as being embedded or pressed into the surface of the red corpuscle; but these observers believe the greater number of parasites, even the young forms, to be endoglobular. When Koch was in this country he was shown models of the red corpuscles with the malarial parasites beneath the surface, and he made the s tatement tha t the parasites were not within the substance of the red corpuscle but attached to the surface.