CHAPTER XXV 



ORDER 3 MICROSPORIDIA BALBIANI 



THE MICROSPORIDIA are far more widely distributed as 

 parasites among various animal phyla than are the Myxo- 

 sporidia. They are, however, typically parasites of arthropods 

 and fishes. Aside from one or two species, al! Microsporidia 

 invade and destroy host cells. Frequently these infected cells 



Fig. 135 Effects of microsporidian infection upon the hosts. (From Kudo). 



a. The central nervous system of Lophius piscatoris infected by 

 Nosema lophii. 



b. A smelt showing a heavy infection by Gluges, hertwigi. 



c. A larva of Culex territans infected by Thelohania opacita. X8. 



d. A simulium larva infected by T. mulHspora. X6. 



e. Portion of the testis of Barbus harbus infected by Plistophora 

 longifilis. Three-fourths natural size. 



f, g,. The normal and hypertrophied nuclei of the adipose tissue of 

 larvae of Culex pipiens, the latter affected by Stempellia magna. 

 X750. 



may show enormous hypertrophy of both the cytoplasmic body 

 and the nuclei (Fig. 135), a characteristic feature of the host 

 reaction toward this particular group of protozoan parasites. 



The microsporidian spore is relatively small. In the vast 

 majority it measures from 3 to 6 microns in length. The spore 



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