102 



THE PROTOZOA 



stance appears to be the passive subject of the changes that are 

 effected. With the achromatinic nuclear elements, extranuclear 

 cytoplasmic substances, such as archoplasm, may collaborate. After 



n 



FIG. 50. Formation of microgametes in Coccidium schubergi. A, Full-grown 

 microgametocyte, with finely-granular cytoplasm and large nucleus con- 

 taining a conspicuous karyosome ; freed from the host-cell. J5, The nuclear 

 membrane has disappeared, and the chromatm, in the form of minute chro- 

 midial granules, is passing out into the cell. C, The chromidia have collected 

 at the periphery of the body ; the karyosome is left at the centre, and has 

 become pale through loss of chromatin-substance. D, The chromidia, seen 

 on the surface of the body, are collecting together into irregular streaks and 

 clumps. E, The chromatin -streaks of the preceding stage are collecting 

 together into patches. F, The patches of chromatin of the preceding stage 

 have become dense and closely packed. G, H, The patches of chromatin 

 take on a definite form as the future nuclei of the miccogametes. /, Two 

 flagella grow out from close to each microgamete-nucleus, and by their 

 activity the microgametes, consisting almost entirely of chromatin, break 

 loose from the body of the gametocyte and swim away. J, Three micro- 

 gametes, more highly magnified ; in each, two flagella arise from the thicker 

 c<nd ; one of the flagella (the shorter) becomes free at once, the other (the 

 longer) runs along the body and becomes free at the hinder end. n., Nucleus, 

 k, karyosome, of the microgametocyte ; n', n', nuclei of the microgametes. 

 After Schaudinn (99); A E magnified 1,000, F 1 magnified 1,500, 

 J magnified 2,250. 



disappearance, as a rule, of the nuclear membrane the achromatinic 

 substance, or the combination of achromatinic and archoplasmic 



