94 W. G. lilDEWOOD AND H. B. FANTHAM. 



7. Arouud the parasite in its various stages (except the 

 amtebula stage) is an ill-defined capsule, partly alveolar, and 

 probably secreted by the cells of the host. 



The systematic position of Neurosporidi u m may be 

 readily determined by reference to the characters summarised 

 above. The somewhat irregular form of the trophozoite and 

 its possession of several nuclei; the appearance of pansporo- 

 blasts, denoting the commencement of spore-formation, at an 

 early stage in the growth of the parasite; the division of the 

 pansporoblast to form many spores; and the intercellular 

 (histozoic) habitat of the parasite; all these are characteristic 

 of the Neosporidia. 



Further, on account of the small, simple uninucleate spores, 

 without polar capsules, the increase in the number of nuclei 

 during the trophic stage, and the segmentation of the full- 

 grown trophozoite into ovoid pansporoblasts, we place the 

 parasite among the Haplosporidia. 



The division of the pansporoblast into many spores is a 

 feature which does not occur in the life-history of the typical 

 Haplosporidian. In Haplosporidium scolopli and H. 

 marchouxi the number of spores formed from each pan- 

 sporoblast is four; in Bertramia it is one. In Rhino- 

 sporidium kinealyi, however, a parasite from the nasal 

 mucous membrane of man, recently described by one of us 

 (Fantham)^ in collaboration with Prof. Minchin, and also by 

 Beattie,^ the portion of the life-history in question finds a 

 fairly close parallel. 



In Rhinosporidium there is a multinucleate trophozoite 

 phase, followed by segmentation into many closely packed 

 pansporoblasts lying within a thin peripheral layer of un- 



1 Mincliin, E. A., and Fantham, H. B., " Khiiiosporidium kinealyi* 

 n. g., 11. sp. : a Sporozoon from the Mucous Membrane of the Septum Nasi of 

 Man," 'Quart. Journ. Micr. Sci.,' n. s., xlix, 3, 1905, pp. 521—532, two 

 plates. 



2 Beattie, J. M., " Rhino spor id i urn kinealji: a Sporozoon from the 

 Nasal Mucous Membrane," 'Journ. Path, and Bact.,' xi, 3, 1900, pp. 270 — 

 275, two plates. 



