928 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
free) of Barbus barbus L. (barbel) from the Rhine, Mosel, and Saar, 
the barbels of the Elbe and Weser territory being free from them 
(Pfeiffer). Also once in heart cavity (Ludwig). In barbels from the 
Marne, probably also from the Aisne and Seine (Railliet). Balbiani 
failed to find “adult psorosperms” in the viscera in Mégnin’s material 
(Mégnin). 
Liver, kidney, spleen, connective tissue of various organs; found in 
ovary by Balbiani.! In one case the myxosporidia and spores were 
lodged in a sort of cavity in the connective tissue of the intestinal wall 
10 em. from the anus. They produced a very conspicuous thickening, 
almost completely obliterating the lumen. 
Pathology—Tumors:? A badly infected barbel showed about 40 
tumors; fully 10 per cent of all the muscular fibers were filled with 
spores. This condition must have resulted from auto-infection. The 
tumors may soften to an irregular stinking abscess containing spores, 
wandering cells, and the large bacilli (Pfeiffer; see below under Ulcers). 
Tumors, usually 10 to 15, ranging in size from a nut to a hen’s egg, 
with avery resistant wall 1 to 1:5 mm. thick; hemispherical or slightly 
elongate; sometimes uniting into patches 17 to 20 mm. long by 7 or 8 
mm. broad in fishes of 2°5 kilos (about 5 pounds) weight. Seales over 
tumor raised, easily detachable, finally falling off. Not all tumors open, 
some fishes dying before the ulcer stage. 
Some fishes die without external tumors, these being found located 
in the viscera (Meuse; Railliet). Uusually of walnut size; sometimes, 
however, 50 mm. long and 20 mm. thick, single or multiple, usually on 
belly or sides; filled with a yellow or caseous purulent mass (Mosel, 
Saar; fide Ludwig). 
1 Fide Thélohan (Annal. de Microgr., 1850, 1, p. 200; Compt. Rend. hebdom. Soe. Biol. 
Paris, 1893, v, p. 268) who refers to Balbiani’s Légons sur ler Sporozoaires. The only 
page of the last work to which the reference could apply is p. 147, and as M. Thélo-_ 
han says (letter to author, 1893), Balbiani is there not at all explicit, 
2The following notes of four cases are from Ludwig. The fish were taken alive from 
the Mosel above Trier, died en route, and were examined the next day: 
1. ¢ 30cm. long; on left side just above ventral fin a tumor 50 mm. long, 40 mm. 
broad, and 30 mm. thick, extending above lateral line; skin and omentum in neigh- 
borhood of tumor normal. 
2. 9 47cm. long; two tumors: (a) on right side above ventral fin, under trunk 
muscles (which latter were, around the tumor, reddened), 45 mm. long, 35 mm. broad, 
and 15 mm. thick; covered by normal skin. Tumor so extended into body cavity as 
to have driven the omentum hernia-like before it. (b) On left side in front of 
pelvic bone, length 50 min., breadth 15 mm.; already opened; orifice 10 mm. in 
diameter with an irregular strongly reddened border, surrounded by reddened skin. 
Cavity of ulcer filled wish bloody mneus, which, apart from the admixture ofblood, 
agreed with the tumor contents. 
3. 9 44cm. long; on left side at level of lateral line, between ventral and anal 
fins, a tumor 25 mm. long, 12 mm. broad, and 12 mm. thick; heart cavity filled with 
same substance as tumor contents. 
4. g 30cm. long; in front of left ventral fin a tumor 35 mm. long, 25 mm. broad, 
and 25 mm. thick, projecting but little externally, but greatly into abdominal cavity. 
