251 



(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. 



Fifr 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 



