232 
A Myxosporidian 
vitch (1917a) and Erdmann (1917) since the first work by Biitschli (1881) on 
the subject. Of the recent workers, Erdmann (1917) states that the polar 
filaments of C. leydigi are composed of glycogen and plastin. That this was 
not the case in the several species of Myxosporidia which I had studied, was 
reported in one of my papers (Kudo, 1921a). The first indication of the forma¬ 
tion of the structure under consideration, is recognized when a deeply staining 
club-shaped mass (Fig. 53) appears in the capsulogenous cell. The nature of 
this substance is not clear, but it is certainly not glycogen or a similar 
substance. On the other hand, since the nucleus is not only closely applied 
to the said mass, but directly connected with it, it is most probably composed 
of chromatin substance and nuclear sap and of the transformed cytoplasm 
of the cell. The mass grows larger; one end becomes much larger than the 
other (Fig. 53). At the same time, the cytoplasm shrinks and a vacuole is 
formed in which the deeply staining substances accumulate. As the mass 
becomes still larger, it bends to one side, assuming a retort shape, the nucleus 
feeding its chromatin granules constantly into the growing mass (Figs. 61-63, 
65). The fine extremity of the mass becomes coiled around the other rounded 
end (Figs. 60, 66-69). When the spiral of the filament is completed, there 
differentiates from the outer region of the mass a sac-like structure which 
surrounds the polar filament (Figs. 60, 66-69). This is the polar capsule. 
Although its length is a moderate one compared with that of several other 
species I have studied (Kudo, 1917, 1918 and 1920a) the polar filament is 
comparatively thick. The nucleus of the capsulogenous cell seems, therefore, 
to be used up entirely in most cases for the formation of the polar capsule 
and polar filament. In mature spores, no remnant of the nucleus of the 
capsulogenous cell, is usually seen (Figs. 78, 87-90, 94, 96-99, 101-103), 
though occasionally this is not the case (Fig. 81). 
During these changes, the sporoplasms, each containing a single nucleus, re¬ 
main separated from each other and without any noticeable change (Figs. 53-77, 
81, 87-90, 94, 96, 97). This is certainly a peculiar feature of the species. Even 
in the completely developed spores, the two sporoplasms remain independent. 
During the formation of spores, the vegetative nucleus of the trophozoite 
remains unchanged in its external appearance. It is, in almost all cases, 
found on one side of the body and usually between the developing spores 
(Figs. 53-60, 81-85, 89). Contrary to the observations made by other authors 
on several species of Myxosporidia, the vegetative nucleus of the trophozoite 
of L. ohlmacheri, instead of undergoing degeneration, grows and increases 
in size as the trophozoite grows and the spore formation proceeds (Figs. 52, 
60, 81-83). This demonstrates that it controls the vital trophic function of 
the vegetative form during the entire period of its existence. A similar state 
has been observed in S. dimorpha (after Davis) and C. coris (after Stempell). 
The necessity of having a functioning vegetative nucleus is also well under¬ 
stood, if one considers the fact that the fully grown trophozoite containing 
two mature spores undergoes active formation of pseudopodia (Fig. 89). 
