224
GLYCOGEN IN EIMERIA TENELLA
[ Vol. XXIV, Part IV,
technique does not differentiate between glycogen, paraglycogen and mucin which
all give similar colour reactions. Negative section controls and preparations sub-
jected to saliva treatment were run side by side at each stage of our study.
Favourable tissue and smears were also fixed in Carnoy's fluid (alcohol, chloro-
form, acetic acid; 6 : 3 : 1). Sections and smears were subsequently stained with
the techniques of Hotchkiss [1948], and Jarvi and Levanvo) [1950] to visualise possibly
all the polysaccharides of the parasite without specific reference to any one of them.
OBSERVATIONS
Sporozoites observed 34 hours after infection, trophozoites, fully formed
schizonts and merozoites resulting from them, remained unstained both in their
nuclei and cytoplasm. Very rarely in some just entered sporozoites, a few red
granules were seen round the siderophilous body. The latter structure consistently
remained unstained. No change was noticed in the host cell nucleus except the
usual hypertrophy.
The smallest second generation trophozoites measuring 3.8 µ along their broadest
diameter, either round or oval in shape, showed distinct fine red granules concentrated
on one side usually quite close to the nucleus while the rest of the cytoplasm remained
unstained. A low power examination of the freshly parasitised region showed
mucosa studded with brick red dots lying in vacuoles. With further growth, red
staining became diffuse in the cytoplasm of trophozoites persisting throughout
its transformation into schizonts. As the quantity of glycogen in the parasite
was very small now, it could only be discerned definitely either in smear preparations
or in sections not counterstained with haematoxylin. But, just before the differentia-
tion of merozoites, red staining suddenly became intense and the mature schizont
appeared as mass of red staining material.
Glycogen in second generation merozoites occurred in a diffuse colloid form.
Merozoites of larger type (14×2 µ in size) had red staining concentrated in an area
just anterior to the nucleus (Plate XI, Fig. 3). Very rarely, a few red granules were
seen at the posterior end also. Sometimes the whole cytoplasm showed a diffuse
colouration. The smaller merozoites (5×1.5 µ) invariably showed glycogen at
either side of the nucleus (Plate XI, Fig. 2).
Fresh preparations of merozoites when treated with Lugol's iodine showed
brown staining granules scattered all over the body particularly in a dense brown
area anterior to the nucleus, though the latter was not coloured.
Soon after entering a cell, second generation morozoites became rounded off
and showed a large red globule filling almost half to two-third of the cytoplasm
of young gametocytes (Plate XI, Fig. 1). Nuclear space remained unstained and
appeared as a vacuole lying on one side, on rare occasions two such red masses
could be seen in one gametocyte. In macrogametocytes glycogen appeared as
a homogeneous colloidal substance which with further growth diffused out into the
cytoplasm. The peripheral globules in macrogametes remained unstained and
appeared as empty spaces. Later on, as macrogametocytes reached maturity,
a differentiation in the centre of the protoplasmic mass occurred showing a clear
nuclear area. Microgametocyte appeared as fluffy or rugged pinkish mass, red