REPRODUCTION AXD THE LIFE CYCLE 



185 



with the mycetozoa, and through these a phylogenetic relationship 

 between the neosporidia and the rhizopocla. This is particularly 

 well illustrated in the case of SchewiakoveUa schmeili, a parasite of 

 copepods where there is not only a multinucleate trophozoite stage, 

 but the parasite differs from all other sporozoa in having a distinct 

 rhizopod characteristic in its contractile vacuole, while it agrees with 

 mycetozoa in that young forms come together and fuse to form plas- 

 modia. A further peculiarity of this organism is the binary division 

 of the spores (Fig. 77). 



In this group of little-known forms, one case of human infection 

 has been reported by Minchin and Fantham ('05). The connective 

 tissue of nasal tumors in natives of India was found to contain quan- 



FIG. 78 



Rhinosporidium kinealyi, Minchin and Fnntliain. i After Mine-hill and Fantham.) 

 segment of a section through a cyst from a tumor of the human nasal septum. The ripe 

 pansporoblasts are accumulated in the centre of the cy.-t and gradually encroach upon the 

 peripheral plasm until all is utilized. One ripe ">pore-morula" is shown on the right. 



tities of haplosporidian parasites Rhinosporidium kinealyi in all 

 stages of development, from young multinucleate organisms to adults 

 filled with pansporoblasts (Fig. 78). The pansporoblasts give rise to 

 sporoblasts (spores) which are formed successively until about a dozen 

 are developed. (As in other myxosporidian pansporoblast formation, 

 the possibility of sexual union of nuclei (autogamy) is not excluded 

 by the authors.) When mature, the cysts appear to burst, the mero- 

 zoites (?) thus being ([distributed to neighboring tissues, giving rise to 

 new tumors by auto-infection. 



In sarcosporidia, including muscle parasites of birds, lower mam- 

 mals and man, the process of endogenous multiplication proceeds in 

 a manner quite similar to that described above. In its earliest stages 

 the parasite appears as a minute white body embedded in the material 



