THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 99 
The discovery of the capsule settles the question in favor of its myxo- 
sporidian nature. It is thus neither a sarcosporidian nor a transitional 
form (Henneguy and Thélohan, 1892). 
Microscopic technique.—Henneguy fixed by alcohol, osmic acid solution, 
Flemming’s, Perenyi’s, or Kleinenberg’s liquids, dehydrated, paraffined, 
sectioned, affixed with Mayer’s albumen, and stained, preferably with 
gentian violet (Ehrlich’s) and eosin. Parasites (also nuclei of muscles, 
connective tissue, epithelia, nerves; which, however, can be washed out) 
violet; muscles rose-red. Picro-carmine; muscles red, spores yellow. 
Safranin; tissue nuclei red, spores same, but fainter. ; 
T. octospora differs from T. giardi in the smaller size of the panspor- 
oblast, and apparently also in the absence of thickening of its mem- 
brane. 
Pathological anatomy.—Macroscopic: Easily recognizable by the chalky 
or porcelaneous opacity’ which forms a constant and characteristic sign 
of the presence of these Myxosporidia. Opacity limited to the muscles 
invaded, consequently varying in extent with the degree of infection; 
in slight (and in the beginning of all) cases being limited to some 
white striz in one or several abdominal segments, or only one or two 
segments (most frequently then the first ones, the disease appearing to 
progress from before backwards) are opaque white. Ad maximum, the 
entire body becomes white except the region of the heart and stomach 
which always, and some parts of the claws, antennz, beak, and abdom- 
inal segments which usually, remain transparent. These exceptions 
constitute the only difference between this condition and the opacity 
produced by heat or alcohol. 
Microscopic.—Low powers: In examining a teased or slightly com- 
pressed muscle fragment, one immediately perceives, besides the normal 
primitive fiber bundles (easily recognizable by their transverse stria- 
tion), elongated spaces parallel to these bundles, contrasting strongly 
therewith, and apparently filled with a peculiar finely granular sub- 
stance. Dimensions of spaces approximating those of the normal 
fiber bundles; their transverse diameter, however, a little greater. 
Number of spaces varying pari passu, andthe intervening sound tissue 
varying inversely, with the intensity of the infection, the opaque spaces 
being in contact or more or less widely separated by sound fiber bun- 
dles. The proportion of the fibrille invaded is best appreciated in 
transverse sections of the muscles. In extreme cases nearly all the 
fibers may be affected. Longitudinal sections show the parasite in the 
form of violet chains between the rose-red normal fibrille (gentian 
violet; safranin). 
Higher powers: At first sight one would believe that each of these 
productions is entirely composed of a parasitic mass interposed 
between the primitive fibers, but a more thorough examination shows 
'The same opacity is found in the muscles of Callionymus lyra, Cottus scorpio, and 
Barbus barbus, and outside the muscles the parasites exhibit the same color. 
