FIG. 1

Experimental P. gibsoni infection

Section of bone marrow. Stain Heidenhain Iron Haematoxylin and eosin ×875

     M.—Macrophages
      M₁—Macrophage containing blood pigment
      R.—Reticular cell with inclusion bodies
      R₁—Reticular cell with nuclear degeneration
      I.B.—Inclusion bodies in intercellular spaces
      N.—Normoblast
      P.— Polyblast (transitional haemocytoblasts)
      H.—Haemocytoblast
      Pig.—Blood pigment

                                             FIG. 2

                                    'Lahore Canine Fever'

Polyblast (reticular) cell from bone marrow

The cell cytoplasm has swollen and ruptured and the cytoplasmic inclusions are
migrating into the intercellular tissue spaces. Note the intact nucleus

                                             FIG. 3

                                    Lahore Canine Fever.'

Polyblast (reticular) cells from the red pulp of the spleen showing cytopalsmic
inclusions