2 5 
(i) The male cell possesses a mass of compact 
chromatin and faintly staining protoplasm. 
(ii) The female cell possesses but little chromatin, 
but stains deep blue (Romanowsky). 
Flagellation. —(i) This can be observed in a 
simple wet film preparation. Make stained specimens 
according to the method given on p. 41, or 
(ii) Use artificial serum (bird’s serum, one part ; 
salt solution, 0’6 per cent., nine parts), and to this 
add a trace of bird’s blood. Make a series of hanging 
drops in moist chambers. Dry, fix, and stain, from 
time to time, according to stage of development, 
observed microscopically. 
Fig. 75 * (Upper line) Proteosoma shewing medium-size Parasite and 
Segmenting Form. (Lower line ) Halteridium young form 
Female and Male Gametes , and Vermicule 
Further stages of development (vermiculi) have 
not been observed on the slide. 
Development of Vermiculi. —(i) Determine what 
species of Culex is the suitable one for the process of 
development. C. nemorosus was used by Koch, in 
Italy. C. fatigans is also a carrier. 
(ii) Collect the Culex that have fed on sparrows, 
etc., roosting at night in trees. The Culex can be 
