Blood corpuscles. Labels: A, magnified about 400 diameters. The red corpuscles have arranged themselves in rouleaux; a, a, colorless corpuscles; 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 seen edgewise. F,G,kH,I, white corpuscles highly magnified.