252 
caught in large numbers in shaded drains, under 
bridges, in outhouses, etc., and excellent material is in 
this way easily got. Identify the species of Culex 
that is infected. 
(iii) For the method of feeding mosquitoes on 
birds’ blood, vide p. 95. 
Twelve to fifteen hours.—Vermiculi in all stages 
of development are found in the stomach ; a conical 
projection arises from the fertilized gamete. This 
gradually elongates, forming a long, curved, oval body, 
the complete vermiculus. The protoplasm is vacuo¬ 
lated, and a nucleus (chromatin) is readily shown by 
staining (Romanowsky). 
The proteosoma vermiculi are larger and more 
slender than those of halteridium. 
Development of Zygotes (one or two days).—The 
vermiculi have disappeared, but in the stomach wall 
are now found transparent, spherical, pigmented 
bodies. 
Three to four days.—The zygotes have increased 
in size, and sporoblasts appear in their interior. In 
the larger forms, signs of further division are seen 
(striation), formation of sporozoits. 
Development of Sporozoits (nine to ten days).—By 
this time the sporozoits have reached the salivary 
glands. Somewhat earlier they can still be found 
amidst the thoracic muscle. Earlier still, they can be 
pressed out of the ripe oocysts in the stomach wall. 
The sporozoits occupy chiefly the middle lobe of the 
gland (Koch). 
Black Spores are found in the larger zygotes. 
They also occur free in the thoracic region (or, 
possibly, in the gland substance). They are brownish- 
black, curved, sausage-shaped bodies, suggesting a 
mycelial nature. It is believed by Grassi that they 
