Plate II.

A.—Stages in Development of Quotidian Parasite.

     1, 2, 3.—Very young forms, actively amœboid, frequently (2 and 3) ring
shaped.

     4.—Older, pigment developed; red cell, small, dark and shrunken.

     5.—About 24 hours, pigment in centre, segmentation commencing.

     6.—Young crescentic body, pigment near one pole.

     7.—Older crescent, with remains of red cell, and velum forming.

     8 to 14.—Bodies of crescentic series.—8, fusiform with red pigment; 9,
crescent with red pigment in centre and double contour; 10 and
11, spherical with double contour, pigment in rings, and budding;
12 and 13, spheres with double contour, and dark pigment massed
in centre; 14, flagellated body.

     15—.Leucocyte containing small parasite.

     16.—Leucocyte containing melanin particles.

B.—Structure of Parasites of Malignant Remittent (stained with Hœmatoxylin
and Eosin,—see text).

     1 to 4.—Young unpigmented parasites, with marked chromophil spot.
5.— Melanin commencing to be formed.

     6.—Two parasites in same cell.

     7 to 10.—A few hours older, vacuoled, pigment more developed.

     11 to 15.—Adult forms; pigment concentrated preparatory to sporing.

     16.—Pale spherical body of crescentic series.

     17.—Sporing form, with pigment in centre and marked chromophil body in
each spore.

     18 to 22.—Crescents in red cells, which still stain with eosin.

     23 to 30.—Various forms of crescentic bodies, uniformly stained.
31.—Melaniferous multinuclear leucocyte, stained with Ehrlich Biondi
fluid.

C.—Capillary from motor cortex of cerebrum, with contained parasite-bearing
red cells (stained with Acid Hæmatoxylin, differentiated and neutra-
lised).

D.—Cells from Red Marrow of Rib (Acid Hæmatoxylin and Eosin).

     1.—Two young parasites in one hæmocyte.

     2.— Mature sporing form.

     3.—Sporulation commencing.

     4.—Small body of crescentic series.

     5.—Crescent.

     6.—Nucleated red cell.

     7.—Eosinophil leucocyte.

     8.—Large phagocytic marrow cell.

E.—Cells from Splenic Pulp. (Acid Hæmatoxylin and Eosin).

     1.—Small nucleated ring-shaped parasite.

     2.—Older form, with melanin scattered through cytoplasm.

     3.—Mature parasite.

     4.—Crescent.

     5.—Nucleated red cell.

     6.—Melaniferous leucocyte.

     7.—Melaniferous splenic macrophage.

F.—Section of Liver in Malignant Remittent Fever.

     Shows irregular dilatation of hepatic capillaries; nuclei and contour of
liver cells indistinct from cloudy swelling, and numerous melaniferous
cells lying in capillaries.