MICROSPORIDIA — PARASITIC IN MOSQUITOES 163 



in Thelohania maenadis and by Debaisieux in T. varians. Yet 

 stages like figures 16, 17, 20, and 21 lead the writer to consider 

 them as stages of division instead of fusion of two forms. The 

 writer once noticed such a form as is shown in figure 24, which 

 may be considered as a preliminary stage of copulation of two 

 isogametes. However, he has no further evidence of the fusion 

 of gametes or the union of two nuclei in the present form. 



The writer had already stated that there appears a narrow space 

 in the developing sporoblast, and that it becomes broader as the 

 formation of the polar filament progresses. Debaisieux ('15) saw 

 probably a similar structure ('canalicule') in the spore of Glugea 

 miilleri, but interpreted the meaning in an entirely different 

 manner. 



The fully mature spore is 12 to 13. 5^ long and 4m broad. It 

 is elongated pyriform and usually bent toward one side. In 

 cross-section it is circular. The posterior end is broadly rounded, 

 while the anterior extremity is less rounded, though not attenu- 

 ated. 



In fresh state, the mature spore shows a great vacuolation in 

 its anterior portion (fig. 56). For about two-thirds its length 

 from the anterior tip, fine irregular lines of fcoiled filament are 

 seen, which become more distinctly visible when the spore is 

 stained; while the posterior third is occupied by a finely granu- 

 lated protoplasmic mass which often contains a refringent body 

 near its extremity. When the fresh spores are subjected to 

 mechanical pressure and are stained by Fontana's mixtures, the 

 extruded polar filament is distinctly recognizable (fig. 57). It 

 is uniformly fine and reaches a length of 230ju. The writer does 

 not think this the average length, but records it here as the longest 

 one found so far. The average length varies from 150 to 200^. 

 This particular spore (fig. 57) shows not only the extruded fila- 

 ment, but also distinctly its remaining part spirally coiled inside 

 of the capsule. The same figure at the same time gives a strong 

 basis on the presence of a polar capsule containing a spirally 

 coiled polar filament. The spore membrane does not exhibit 

 any sutural line as was recognized in the spore of Thelohania 

 giardi (Thelohan, '95) or of Thelohania sp. (Mercier, '08). 



