PLATE 6 
EXPLANATION OF FIGURES 
1,2, and3 Types of flagellate bodies from Gregarine cyst, X 1400. 
4 Most common type of flagellate body, 2200. 
5 Diagram of histoblasts of mature healthy Simulium larva; r.f., respiratory 
filament (pupal) histoblast; w, wing histoblast;h, halter histoblast; 1b, 2b, 3b, 
leg histoblasts. 
6 Diagram of histoblasts of full grown Simulium larva containing Microspor- 
idia, lettering as in fig. 5. 
7 Diagram of histoblasts of full grown Simulium larva containing ‘Gregarine;’ 
lettering as in fig. 5. 
8 Longitudinal section through one half of the proventriculus and cardia 
(see text figure, page 00, for explanation). 
9 Diagram of a section of the mesenteron. p.m., peritrophic membrane; 
c.m., circular muscles; /.m., longitudinal muscles. 
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