THE MYXOSPORTDIA, OR PSOROSPERMS OF FISHES. 229 



Opening of the tumors: The active agents in the puriform transfor- 

 mation and opening- of the tumor are the bacilli first observed by Pfeif- 

 fer in the ulcer contents. These are only found in the myxosporidian- 

 infected muscles, never in other organs. The i)resence of these microbes 

 either prevents connective tissue proliferation entirely, or prevents it 

 from becoming complete, the tissue undergoing gangrene (a digestion- 

 liquefaction, so to speak), Avhich soon results in the destruction of the 

 overlying tissues. 



Subsequently the bacilli were studied by Thelohan (see synonymy, 

 1893) who observed two kinds of them: 



1. Bacilli: Large, motile, as long as the spores, showing with hiematoxyliu 4 or 5 

 red granules, and a short flagellum; frequently several cohere by their surfaces; 

 also long separated threads occur (Pfeifter, 1891, p. 105). 



Length 6 /< ; sometimes isolated, sometimes in linear colonies, no motion seen ; rap- 

 idly liquefying gelatin upon which it gives large, slightly yellowish- white colonics; 

 in rabbits i^rovoking a small, verj- limited abscess; staining easily with methylen 

 blue, gentian violet, fuchsin, etc. (Thelohan, 1893). 



2. Cocci: More rarely, sometimes with last, sometimes alone, another species 

 consisting of Cocci isolated or united under the form of Streptococci or Diplococci 

 occurs. 



Ulcers: The tumors subsequently soften and burst, forming deep 

 crateriform bloody-bordered ulcers tilled with a yellowish jDurulent 

 mass consisting of spores and of cell detritus. Among the latter large 

 bacilli crawl. 



Cell infection : The primary seat of infection is the interior of the 

 muscle cell. Myxosporidia are found within well-preserved (distinctly 

 transverse-striate) or markedly atrophied muscular fibrilhe; also be- 

 tween healthy flbrillfe. Atrophied muscle-cells are seen containing long 

 rows of well-developed spores, which, on account of the absence of 

 filaments within the capsules, Pfeifter inclines to believe have reached 

 their present position by a general immigration. In places the fibrillae 

 are beaded, such muscle bead-strings being ordinarily heaped near 

 together in the neighborhood of the hard cysts. Around the cysts the 

 muscular tissue is infiltrated with blood, the infiltration, where super- 

 ficial, being visible through the skin. Near the ulcers the muscular 

 substance is broken up, loosened, fatty-degenerated, and contains blood- 

 colored tubes with numerous myxosporidia not yet encapsuled and also 

 well-developed spores. 



Thelohan ' says : 



In the ovary they are very frequently encountered. M. Balbiani has studied 

 them in the ovary of the barbel and he has seen that the psorospermic matter does 

 not confine itself to traveling via the connective tissue, but often invades the young 

 ovules. 



Pathological anatomy r — The presence of the parasite in the primitive 

 muscle fiber seems to lead rapidly to degeneration. On examining 



' Annal. de Microgr., 1890, ix, p. 200. 



■^Description Thdlohan's (Compt. Kend. hobdom. Soc. Biol. Paris, 1893, V, pp. 

 267-270). 



