Fic. 13. Diagram of life 
cycle of Eimeria  (cocet- 
dium) avium. (Fantham) 
B-H. Illustrate the asex- 
ual reproduction (schizog- 
ony) of EB. avium. Epithe- 
lial host cells diagrammat- 
ically outlined. 
J-L. Illustrate the pro- 
duction of sexual forms 
(gametogony). 
N-T. Illustrate spore 
formation (sporogony). 
A. Sporozoite or primary 
infecting germ which pene- 
trates the epithelial cell of 
the duodenum of the host. 
B. Sporozoite curving on 
itself before becoming 
rounded within the host 
cell. ; 
C. Young, growing para- 
site. 
D. Fully grown parasite 
(Trophozoite) . 
E. Schizont, with numer- 
ous daughter nuclei peri- 
pherally arranged. (Seen 
in transverse section.) 
F. Schizont, showing far- 
ther differentiation of mero- 
zoites. 
G. Merozoites arranged 
“en barillet,” about to issue 
from the host cell. 
H. Free merozoites. 
Ig. Young macrogame- 
tocyte with coarse granules. 
I¢v. Young microgametocyte with fine granules. 
J%. Growing female mother cell, showing chromatoid and plastinoid granules. 
Jo. Microgrametocyte with nucleus divided to form a number of bent, rod- 
like portions, the future microgametes. 
K?. Macrogamete which has formed a cyst wall for itself but left a thin 
spot for the entry of the microgamete. 
j K¢é. Microgametocyte with many biflagellate microgametes about to separate 
Tom it. 
L. Fertilization. One microgamete is shown penetrating the macrogamete, 
while other male cells are near the micropyle but will be excluded. 
M. Fertilization. The male pronucleus is lying above the female chromatin. 
Degenerating microgametes are shown outside the odcyst. 
N. Odcyst (encysted zygote) with contents filling it completely. 
O. Odcyst with contents concentrated, forming a central, spherical mass. 
Many such cysts seen in infected cecal droppings. 
P. Oécyst with four nuclei. 
Q. Odcyst with contents segmented to form four rounded sporoblasts. (As 
seen in fresh preparations.) 
R. Odcyst with four sporoblasts which have grown oval and are becoming 
sporocysts. 
S. Odcyst with four sporocysts, in each of which two sporozoites have dif- 
ferentiated. 
T. Free sporocyst in which the sporozoites have assumed the most suitable 
position for emergence. 
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