||P.866 left column top paragraph: "Studies on the morphology of white blood cells (WBCs) are the first step towards development of quantitative models describing leukocyte dynamics in the microcirculation and in the extravascular space. Hematology textbooks [refs 1-3] provide a general description of human leukocytes, but very little quantitative information about their morphology. Usually the dimensions of the WBCs, as seen on blood smears, are reported to fall between 10 and 20 µm,
despite the fact that these dimensions are incompatible with a normal flow of WBCs through capillaries with diameters smaller than 8 µm [ref 4]. On a blood smear, many leukocytes are severely deformed into a pancake shape [refs 3,5,6], whereas in vivo WBCs are spherical and their diameters in homologous plasma are considerably less than 10 µm."