THE MYXOSPORIDIA, 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 presence 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), which soon results in the destruction of the 
overlying tissues. 
Subsequently the bacilli were studied by Thélohan (see synonymy, 
1893) who observed two kinds of them: 
1. Bacilli: Large, motile, as long as the spores, showing with hematoxylin 4 or 5 
red granules, and a short flagellum; frequently several cohere by their surfaces; 
also long separated threads occur (Pfeiffer, 1891, p. 105). 
Length 6 4; sometimes isolated, sometimes in linear colonies, no motion seen; rap- 
idly liquefying gelatin upon which it gives large, slightly yellowish-white colonies; 
in rabbits provoking a small, very limited abscess; staining easily with methylen 
blue, gentian violet, fuchsin, etc. (Thélohan, 1893). 
2. Cocci: More rarely, sometimes with last, sometimes alone, another species 
consisting of Cocci isolated or united under the form of Streptococci or Diplococei 
occurs. 
Ulcers: The tumors subsequently soften and burst, forming deep 
crateriform bloody-bordered ulcers filied with a yellowish purulent 
mass consisting of spores and of cell detritus. Among the latter large 
bacilli crawl. 
Cell intection: 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 fibrille; also be- 
tween healthy fibrille. Atrophied muscle-cells are seen containing long 
rows of well-developed spores, which, on account of the absence of 
filaments within the capsules, Pfeiffer inclines to believe have reached 
their present position by a general immigration. In places the fibrille 
are beaded, such muscle bead-strings being ordinarily heaped near 
together in the neighborhood of the hard cysts. Around the eysts 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. 
Thélohan! 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.?—The presence of the parasite in the primitive 
muscle fiber seems to lead rapidly to degeneration. On examining 
1Annal. de Microgr., 1890, 11, p. 200. 
>Description Thélohan’s (Compt. Rend. hebdom. Soc. Biol. Paris, 1893, v, pp. 
267-270). 
