285] 



STUDIES ON MYXOSPORJDIA—KUDO 



47 



THE SPORE 



As will be shown later (page 52-55), the spore stage is still the only 

 constant character by which various forms of Myxosporidia are identified 

 from each other. For this reason it is necessary to have a clear conception 

 of the form and structure of the spore and at the same time to define the 

 terms used in the present paper, even tho they have commonly been 

 used heretofore. 



Anterior end 

 Foramen of polar capsule 



Shell 

 sutural ridge 



Polar capsule 

 Coiled polar filament 



Nuclei of sporoplasu 

 Sporoplasm 



lODINOPHILOUS vacuole 



Posterior end 



A B 



Texttigure 

 Diagrammatical front [A] and side [B] views of a Myxobolus spore. 



(For further explanation see following pages.) 



The spore of Myxosporidia is covered by a shell, which is composed 

 of two valves usually symmetrical in form and size that come in contact 

 in the sutural plane. The sutural line is straight in most cases, tho some- 

 times curved like an S. It is more or less thickened, forming the sutural 

 ridge. The sutural ridge is to be made out clearly in fresh as well as in 

 stained preparations and furnishes important data in regard to the classi- 

 fication of the parasite. The thickness of the shell- valve is usually uniform; 

 in some species (Myxobolus), however, it may differ slightly in different 

 parts of the shell. Besides, in many species of Myxobolus, the shell 

 differentiates a small triangular intercapsular appendix on the inside at the 

 anterior end directed posteriad between two polar capsules. 



The form of the spore varies greatly owing to the shape of the shell 

 together with its variously developed appendages; 1) lateral appendages 

 as in Ceratomyxa, 2) anterior processes as in Myxoproteus, 3) posterior 

 processes as in Wardia (fringe-like), Mitraspora (filiform), Hoferellus 

 (spinous), Henneguya (tail-form), etc. 



