228 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



free) of Barhus harbus L. (barbel) from the Rhine, Mosel, aud 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 (Ilailliet). Balbiani 

 failed to find " adult psorosperms " in the viscera in Megnin^s material 

 (Megnin). 



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 cm. 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 sij^e from a nut to a hen's ^^g, 

 with a very resistant wall 1 to 1-5 mm. thick; hemisi)herical or slightly 

 elongate; sometimes uniting into i)atches 17 to 20 mm. long by 7 or 8 

 mm. broad in fishes of 2-5 kilos (about 5 pounds) weight. Scales 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). 



^Fide Thelohan (Annal. de Microgr., 1890, ii, p. 200 ; Compt. Rend, hebdom. Soc. Biol. 

 Paris, 1893, v, p. 268) who refers to Balbiani's Lei^ons stir ler Sporozoa'ncs. The only- 

 page of the last work to which the reference coald apply is p. 147, and as M. Th61o- 

 han says (letter to author, 1893), Balbiani is there not at all explicit. 



2 The 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. $ 30 cm. long; on left side just above ventral fin a tumor 50 mm. long, 40 mm. 

 broad, and 30 mm. thjck, extending above lateral line ; skin and omentum in neigh- 

 borhood of tumor normal. 



2. 9 47 cm. long; two tumors: («) 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. (&) On left side in front of 

 pelvic bone, length 50 mm., breadth 15 mm.; already opened; orifice 10 mm. in 

 diameter with an irregular strongly reddened border, surrounded by reddened skin. 

 Cavity of ulcer filled wi»h bloody mucus, which, apart from the admixture ofblood, 

 agreed with the tumor contents. 



3. $ 44 cm. 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. ,? 30 cm. 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. 



