258 



THE SPOROZOA 



dancing. Often it constricts itself into two or more parts, which 

 may reunite. . . . Disintegration and death are the inevitable 

 fate of these remains of the flagellated body, even if it escapes for 



FIG. 74. 



Formation of gametes, and fertilisation, in Halteriilmm(\>a.r. birds), after Macallum. a, female 

 gametocyte in a blood-corpuscle. 6, the same assuming the spherical form, c, the same in the 

 spherical condition and freed from the disintegrated blood -corpuscle, d, mature male game- 

 tocyte in a blood -corpuscle, e, the same assuming the spherical form. /, the same freed from 

 the corpuscle, throwing out " flagella" or male gametes, g, male gametes swarming round a 

 female, which one of them (fl) is actually penetrating, h, the zygote throwing out a proto- 

 plasmic process on one side (the right), i, the zygote transformed from an inactive sphere into 

 a motile " vermicule," moving forwards, with the melanin-pigment gathered at the posterior 

 extremity. N, nucleus of the blood-corpuscle ; m.p, melanin-pigment ; fl, male gametes. 



