Blood plates are usually described as from one to three microns in diameter. The accompanying photographs* demonstrate that they are often much larger than this, with a good deal that suggests cell-structure.
The blood in which the platelets here reproduced were found was from three cases, one of pernicious anemia, one of splenic anemia and one of severe secondary anemia. Using a modification of Wright's method of staining I have obtained similar plates in cases of malaria, myelogenous leukemia and in normal blood. With this stain the definite, usually rounded outline of the periphery is distinctly shown. In most of the figures hitherto published the edges of the plates are jagged and irregular.
Why are these plates so much larger than those usually described and pictured? Their size is probably due in part to squashing, as there are more large ones near the thin edge of the blood-smear where the
ROWLEY MW. NOTE ON THE MORPHOLOGY OF BLOOD PLATES.. JAMA. 1906;XLVI(10):699. doi:10.1001/jama.1906.62510370005001a