THE SPOROZOA 257 



then becomes fragmented, and the chromatin-granules, each still 

 half the size of those originally present, scatter themselves in 

 the cell and become the nuclei of microgametes, which are not 

 separated off simultaneously, but one by one, in an irregular 

 manner (Fig. 75, h, i). In the macrogametocytes the entire nucleus 

 divides into two, and one half degenerates, the other half be- 

 coming the pronucleus of the macrogamete (Fig. 75, k, I). In 

 Haemoproteus ( = Proteosoma), however, the maturation of the 

 macrogamete takes place, according to Schaudinn [93], by ex- 

 trusion of the karyosome, as in Coccidium. 



It is common for the male and female gametocytes to be 

 distinguishable from one another by well-marked characters. The 

 microgametocytes have finely -granulated, hyaline protoplasm, 

 while that of the macrogametocytes is more coarsely granulated, 

 differences which have a considerable effect upon their staining 

 properties in microscopic preparations. On the other hand, the 

 grains of melanin-pigment are generally larger and more numerous 

 in the microgametocytes. In Halteridium the form of the nucleus 

 differs in the two sexes of the gametocyte (Fig. 79), and there is 

 consequently also a difference in the arrangement of the melanin- 

 granules, which in the male elements are placed at the two poles 

 of the body, but in the female gametocytes are evenly scattered 

 in the protoplasm. 



The microgametes in all known cases are without any true 

 flagella, like those of Benedenia and Adelea amongst Coccidia, but 

 while in the human parasites and in the allied genera from birds 

 they are long, slender, and flagelliform, in Lankesterella they are 

 described as minute oval bodies, capable of amoeboid movement. 

 The formation of the male gametes, the so-called " flagella," is a 

 very striking and characteristic phenomenon, easily observed in the 

 Haemosporidia of warm-blooded vertebrates, and described in 

 many forms since it was first seen by Laveran. Macallum [83] 

 gives the following graphic description of the process : 



" The adult organism is seen to draw itself together into a 

 sphere within the red corpuscle, and sometimes immediately, but 

 more often after a short delay, it begins to be greatly agitated, 

 the pigment dancing about, and the surface of the sphere taking 

 on an active undulating motion, which lasts but a short time, for 

 the organism suddenly bursts from the corpuscle, scattering the 

 remains of the latter, and in its place beside the nucleus of the 

 corpuscle, which now lies free in the plasma, it throws out four 

 or more flagella, which thrash about wildly, and sooner or later 

 become detached and wriggle away. The sphere is much reduced 

 in size by this throwing out of flagella, and the pigment is con- 

 centrated. . . . The remains of the sphere continue to be agitated, 

 and after the loss of the flagella, its pigment sets up a most active 



17 



