18 



NOTES ET REVVE 



long (figs I and ii), flattcned out proximally but tapeiing to very fine 

 ends. They show up more eleaiiy when dilute lodine solution is run 

 into the'preparation and occasionally the polar filament is shot out from 

 the opposite end (fig. ii). This thread is of uniform diameter throughout 

 its length of 30-40 •^., thereby differing from the tails which 

 are wider proximally. Ordinary blue black ink is an 

 excellent stain for showing up the délicate tails of thèse 

 spores as was found also for Lithocystis and Urospora 

 (PiXELL Goodrich, 1915 a). Iron haematoxylin also stains 

 the tails but is very easily washed out of them with iron 

 alum solutions, and they only show faintly, if at ail, after 

 using the ordinary counter stains. Consequently in dif- 

 erentiated films mounted in a refractile médium such 

 as Canada balsam, the tails are practically invisible. 

 Similarly they stain so faintly with Giemsa's mixture, 

 even after many hours, that they are again very easily 

 overlooked. Thèse facts account perhaps for their not 

 having been described by earlier observe rs, for there can be 

 no doubt, I think, that the parasite is Thdohania octos- 

 pora. One wonders whethcr possibly there may not be 

 tailed spores in some other species of Thelohania, or even 

 in other Microsporidia. Anyhow this is. I believe, the 

 first recorded instance of a tailed spore occurring among 

 true Microsporidia and furnishes another point of resem- 

 blance between thèse parasites with minute spores pro- 

 vided with a polar filament and the family Haplospori 

 rliidae (Caullery and Mesnil 1905) many members of 

 which hâve tailed spores but never a polar filament. This 

 resemblance supports Debaisieux's conclusion from his 

 récent cytological work on H. chitonis (1919. p. 1401), 

 that the genus Haplosporidium should be included in a sub-order of 

 the Microsporidia. No doubt he is right too in pointing out the great 

 likeness between the gênera Minchinia and Haplosporidium. and in 

 wishing to get rid of the former. Not having studied the other species 

 of Haplosporidium at first hand when I wrote the paper to which he 

 refers (1S15 b) l did not feel myself called upon to eliminate the genus 

 Minchinia named in honour of the late Professor Minchin to whose 

 inspiration I owed so much when starting work on the Protozoa. 



Fig. II. The same 

 after t reatmi^nt 

 with lodine and 

 ink showi nj^ 

 th(' polar flla- 

 nu'nt extruded 

 from the oppo- 

 site end from 

 the tails. 



