234 
A Myxosporidian 
in two points near the ridge and midway between the anterior and posterior 
ends. Along the lateral surface, the majority of the striae run parallel to each 
other, although not infrequently the regularity is broken by short longitudinal 
striae near the posterior end (Fig. 100). These striae appear as fine spinous 
projections around the entire margin of the spore in its optical section (Figs. 90, 
92, 94). The number of striae on each valve varies from 25 to 35. 
Each spore contains two polar capsules in its anterior half. They are 
spherical in shape, and are in most cases of equal dimensions in one spore. The 
wall is very thin and the coiled polar filament can distinctly be seen in vivo. 
The polar filament is spirally coiled usually from four to five times, though 
rarely up to eight times. It always leaves a considerable space between it and 
the wall of the polar capsule. The coiled condition of the filament gives further 
evidence in support of my observations made on other species (Kudo, 1920a). 
There is no central axial portion around which the filament might be coiled 
as was supposed by some authors such as Awerinzew (1909) and Stempell (1919) 
on the same structure in other species. 
The polar filament penetrates through the capsule at its anterior part, and 
is connected with its foramen at the anterior tip of the spore membrane and 
outside of the thickened portion (Figs. 73, 75, 88, 96). The continuity of the 
polar filament with the capsule and further with the foramen in the spore 
membrane, has long been known and many authors referred to the structure 
mainly showing the relation in the front view of the spore as shown in my 
Figs. 73, 75 and 88. Joseph (1907) saw the foramina of spores of Chloromyxum 
protei, and gives two excellent microphotographs. 
In section preparations I have frequently noticed such parts of spores as 
are shown in Figs. 79 and 80. These are tangential sections of the spore mem¬ 
brane through the anterior tip. That this is the case is easily seen by the 
presence of a more deeply stained area on both sides of the sutural line, which 
corresponds to the anterior thickening in the shell-valves, by the direction of 
the striae, and further by tracing the rest of the spores in the adjacent sections. 
These foramina are very small openings situated on either side of the sutural 
plane and almost equidistant to it. 
The extrusion of the polar filaments was easily induced (see p. 223). 
The most striking feature of the spore which commands especial attention 
is its sporoplasms. Ohlmacher who only studied stained sections made from 
the infected kidneys of Bufo lentiginosus which were fixed with absolute 
alcohol, stated that ‘’in the case in which this substance (protoplasmic mass) 
was less in amount, a well defined segmentation was frequently noted; the 
line of division extending through the middle of the mass, each half of the 
divided mass enveloping a pole corpuscle (polar capsule) in the form of a well 
defined crescent.” I have paid little attention to this statement because the 
kidneys were fixed with absolute alcohol which might have caused the “seg¬ 
mentation” in Ohlmacher’s preparations, and also because Whinery, studying 
fresh spores under Ohlmacher’s direction, did not emphasize this appearance. 
