[W/K] :: White blood corpuscles

  Corpuscle \Cor"pus*cle\ (-p[u^]s*s'l), n. [L. corpusculum, dim.
     of corpus.]
     1. A minute particle; an atom; a molecule.
        [1913 Webster]
  
     2. (Anat.) A protoplasmic animal cell; esp., such as float
        free, like blood, lymph, and pus corpuscles; or such as
        are imbedded in an intercellular matrix, like connective
        tissue and cartilage corpuscles. See Blood.
        [1913 Webster]
  
              Virchow showed that the corpuscles of bone are
              homologous with those of connective tissue.
                                                    --Quain's
                                                    Anat.
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     3. (Physics) An electron. [archaic]
        [Webster 1913 Suppl.]
  
     Red blood corpuscles (Physiol.), in man, yellowish,
        biconcave, circular discs varying from 1/3500 to 1/3200 of
        an inch in diameter and about 1/12400 of an inch thick.
        They are composed of a colorless stroma filled in with
        semifluid h[ae]moglobin and other matters. In most mammals
        the red corpuscles are circular, but in the camels, birds,
        reptiles, and the lower vertebrates generally, they are
        oval, and sometimes more or less spherical in form. In
        Amphioxus, and most invertebrates, the blood corpuscles
        are all white or colorless.
  
     White blood corpuscles (Physiol.), rounded, slightly
        flattened, nucleated cells, mainly protoplasmic in
        composition, and possessed of contractile power. In man,
        the average size is about 1/2500 of an inch, and they are
        present in blood in much smaller numbers than the red
        corpuscles.
        [1913 Webster]