NBUROSFORIDIUM. 87 



and easily stained, while in the one-cell or oval corpuscle 

 stage the protoplasm is hyaline and only slightly granular, 

 and does not stain deeply. Several young trophozoites may 

 occur in one space (fig. 6). 



Further nuclear division rapidly takes place, and multi- 

 nucleate trophozoites, spherical, ovoid, or cylindrical in shape, 

 are found with their many nuclei embedded in a more or less 

 rounded or slightly lobulated mass of deeply-staining granular 

 protoplasm (figs. 8 aud 9). The multinucleate trophozoites 

 correspond with the "plasmodium" stage of the Haplosporidia 

 of Caullery and Mesnil,^ though they are not markedly irregu- 

 lar or amoeboid in outline. These trophozoites are 30 /x to 

 40 // long, and 2o fx to 35^ broad. 



A '' Plasmodium " may be formed by the nuclear division 

 and growth of the oval corpuscle or amtebula that constitutes 

 the earliest stage of the parasite, Tt may also be formed by 

 the fusion and growth of several young trophozoites (fig. 7), 

 as can be seen by careful examination of a series of sections 

 passing through a cavity containing several parasites at this 

 stage. Such a fusion or concrescence approximates very 

 closely to the formation of a true plasmodium. 



In the multinucleate trophozoite phase the protoplasm of 

 the parasite is not surrounded by a cuticle, and Neuro- 

 sporidium hereby differs from such a type as Bertramia, 

 which it otherwise much resembles at this stage. The proto- 

 plasm is opaque, and crowded with closely distributed granules. 

 Around each nucleus, however, is usually an area of clear 

 protoplasm (fig. 8). Some of the nuclei are rather large, 1 /u 

 to l'5ju, or even 2ju in diameter, but no definite nucleolus or 

 karyosome is visible ; the chromatin of these nuclei seems to 

 be evenly distributed. No refringent granules such as occur 

 in Bertramia asperospora^ were noticed in the deeply- 

 staining protoplasm. It is to be noted, however, that while 



» Caullery, M., and Mesnil, P., " Recherches sur les Haplosporidies," 

 'Arch. Zool. Exp. et Gen.,' iv, 1905, pp. 101 — 181, three plates. 



2 Minchin, E. A., " Sporozoa," Lankester's 'Treatise on Zoology,' part 1, 

 fasc. 2, 1903, p. 310. 



