THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 289 



attached firmly to Distoma folium (frequently found in the pike's blad- 

 der) ; also attached to other myxosporidia. Observed by Biitschli in 

 December. 



All individuals of Luci^is from the Ehine and Saar have myxospo- 

 ridia in the bladder, while those from the Elbe and Weser territory only 

 exceptionally show them (Pfeiffer, 1891, p. 110). 



Perrier erroneously cites the habitat as the air Madder. 



Pathology (Pfeifter). — The coarser anatoinical details can be seen 

 (under 300 or 400 diameters) by carefully stretching a bladder tightly 

 over a cork, j^lacing a cover glass underneath, brief fixation, and hard- 

 ening by alcohol and staining. Control experiments may be made by 

 maceration in diluted acetic acid. The infection of the bladder was 

 also followed by capillary cultures. 



Mucous membrane, when slightly affected, showing individual clusters 

 of -4, 5, 100 or more epithelial cells infected with myxosporidia; thence 

 all grades of hypertrophy (up to 10 to 30 times the normal size) can be 

 traced. 



Hypertrophy of epithelial cells: When shght, the cells are swollen, 

 shining, apparently lobed. Pfeifier failed to differentiate the nucleus 

 and the intruder, probably owing to early succumbing of the nucleus. 

 With greater hypertrophy the cells are filled with and overdistended 

 by the parasites ; subsequently, continued growth of the myxosporidium 

 ruptures the cell membrane; the myxosporidium flows ama^boidly out in 

 grotesque shapes, and immediately differentiates its hyaline ectoplasm; 

 rupture of cell membrane visible under the microscope. Hjcmatox^'lin 

 or phloxinred-methylenblue stains a narrow-bordered, dark globule in 

 the interior of the swollen epithelial cells; nucleus of latter invisible; 

 largest cells indicating, by ragged coloring of contour, the degeneration 

 of the ei^ithelial remains. 



Effects (of this species??). — Of late years dead i)ike and perch have 

 frequently floated down the Mosel and the Ehine. It is doubtful 

 whether the disease here is the same as the muscle infection of the 

 barbel. According to a statement [unpul)lished, I infer] by Dr. T. W. 

 Miiller in Greifswald, the spore found in the flesh of the pike is not the 

 saTue as that of the barbel, but is formed upon the type of jM. lieber- 

 JcUhnii (Pfeifier).^ 



Whether the ])ike and perch in the Mosel die from myxosporidiosisis 

 unknown With the i^erch, fungous disease concurs (Ludwig).* 

 101. Myxidium ? ? incurvatum Thdlohaii, 1892. 



CoiJipt. Rend. Acad. Sci. Paris, cxv, pp. 1093-109'1. 



Cyst, probably none. 



Myxosporidium. — Snmll, feebly motile. Ectoplasm (in sections) very 

 clearly striate. Pseudopodia lobed, sometimes fuming a bristly, shaggy 

 coat, as in Myxidium lieberJciihnii. 



' Die Protozoan als Krankhoitserreger, 1892, 2 ed.j p. 105. 

 'Jahresber. d. rbcin. Fiscli.-Vereius Bonn, 1888, pp. 27, 28. 

 FO ID 



