254 



(ii) In fresh specimens the female gamete is 

 finely granular, and the pigment is frequently scattered 

 throughout. On staining, a small amount of chromatin 

 is shewn, while the protoplasm takes on a dee-p blue 

 colour. 



Flagellation. Select an infected bird that shews 

 numerous gametes in each field. Proceed in the same 

 way as in Proteosoma. The gametes first become 

 spherical and then escape from the red cell. The 

 pigment of the male gamete displays violent movement, 

 and in a few minutes four to eight flagella are extruded. 

 The motion of these is at first so rapid that they 

 cannot be distinguished, but the corpuscles in the 

 neighbourhood are seen moving. In a few minutes 

 one or more breaks off, and if, fortunately, a female 

 gamete is in the same field, the loose flagellum (mikro- 

 gamete) can be seen entering the female. The 

 pigment of the latter shews active movements at this 

 stage. 



Vermiculi. The formation can readily be 

 observed on the slide. A conical projection forms at 

 one point of the fertilized gamete (copula). This 

 elongates slowly and gets curved, forming an egg- 

 shaped or spindle-shaped mass. The conical portion 

 eventually separates, leaving behind the remains of 

 the cell with the pigment. The vermiculus is thus 

 at first unpigmented, but later again it is pigmented 

 (Koch). In the fresh specimen the protoplasm appears 

 vacuolated, and has a nucleus which is readily stained 

 by Romanowsky stain. 



Note that the vermiculus (or ookinet) shews 

 forward, rotatory, and peristaltic motions. 



Development in' the Fly. The brothers Sergent 

 have shewn that infection in the case of H. columbae 

 of the pigeon is transmitted by a Hippoboscid, Lynchia 



