Blood corpuscles (cells). Labels: A, magnified about 400 diameters. The red corpuscles have arranged themselves in rouleaux; a, a, colorless corpuscle; B, red corpuscles more magnified and seen in focus; E, a red corpuscle slightly out of focus. Near the right -hand top corner is a red corpuscle seen in three-quarter face, and at C one is seen edgewise. F, G, H, I, white corpuscles highly magnified.