NEUROSPORIDIUM. 89 



trophozoite divides into a number of bodies, each of which 

 becomes a single spore, yet in the case of Haplospori- 

 dium scolopli and H. marchouxi^ the bodies into which 

 the trophozoite divides undergo each a division into four 

 spores." The "bodies" in question ave thus pansporobhists 

 in the sense described above. 



In Neurosporidium a definite segregation of the cyto- 

 plasm of the trophozoite around the nuclei marks the begin- 

 ning of the formation of pansporoblasts (figs. 7, 10, and 11). 

 The general shape of the trophozoite at this stage is ovoid 

 (fig". 11), or sometimes nearly sausage-like (fig. 10). The pan- 

 sporoblasts are uninucleate cells with hyaline protoplasm, 

 lying embedded in the opaque, granular protoplasm of the 

 trophozoite. They are irregularly, but fairly closely packed 

 in this granular mass, sometimes slightly more crowded 

 together at the periphery of the trophozoite than in the 

 centre (fig. 10). They are spherical or oval in shape, and Sju 

 or 4jU in diameter. 



The pansporoblasts in some trophozoites are very quickly 

 formed, the phase of nuclear division being rapidly passed 

 through, or even omitted, since this stage may be reached, 

 in true "plasmodial" manner, by the fusion of several 

 young trophozoites, all lying within a common cavity in the 

 host-tissue, as already noted. By careful examination of 

 series of sections, what appears to be the fusion of such 

 masses of young trophozoites can be seen, and a stage in the 

 process is shown in fig. 7. 



The cavity in the host-tissue enclosing the parasite in- 

 creases in size as the growth of the parasite proceeds ; in all 

 probability the parasite causes progressive degeneration of 

 the neighbouring host tissue. 



Up to this point the development of Neurosporidium 

 has been simple, in many respects closely following that of a 

 typical Haplosporidian, such as Bert rami a. The mode of 



1 Caullery and Mesnil, loc. cit., p. 114 and p. 117. 



- In Haplosporidia there is no visible distinction between sporoblast and 

 spore; the former passes directly into the latter. 



