THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 303 



Plate 43. 



Figs. 1-5. Myxidium lieherkvhvii. 



1. Myxosporidia (after Lieberkiihn. X 1). 



la. Showing tlie ,u,raiiule-free, pronged end by which attachment is effected, 



and a pansporoblast containing 2 spores. X 330. 

 lb. Myxosporidiain whicli has mostly broken up into pansporoblasts, x 900. 



2. Specimen covered with transverse wrinkle-like elevations; atone end some 



psendopodia (after Biitschli. X f). X 160. 



3. Three successive stages in the development of clear ectoplasmic pseudopodia 



at one end of a large myxosporidium (after Biitschli. X 1). 



4. Small myxosporidium attached to a nucleated bladder cell (after Biitschli. 



X 1). 



5. Strongly amoeboid- branched specimen (after Biitschli. X §). X about 90. 



Plate 44. 



Figs. 1-5. M/ixidium lieherJciihnii (after Biitschli. X 1). 



la,b. Large forking myxosjioridia; a, with fine hair-like ectoplasmic pro- 

 cesses. 



2. Large myxosporidium, showing interlaminie between ectoplasm and endo- 



plasm. 



3. Portion of border of myxosjjoridium showing the peculiar canaliculate struc- 



ture mentioned on p. 285. 



4. Part of border of large myxosporidium'with branched horn-like ectoplasmic 



processes. 

 5a-d, Four yellowish fat globules, inclosing hai'matoidiu crystals. 



Plate 45. 



Figs. 1-3. MyxUlhim lieherkiilinii (after PfeitFer. X 1). 

 la. Smallest form. 

 lb. Small form with fat globules, haematoidin crystals, with only 1 pair of 



ripened spores; ectoplasm evident. 

 Ic. Motile myxosporidium with very strong soap-bubble-like ectoplasm; in its 



interior a well-preserved red blood corpuscle, with fat globules and hiema- 



toidin inclusions. 

 Id. Specimen with amn?boid pseudopodia. 

 le, f. Large forms with scattered spores. 

 Ig. Carmine staining after removal of fat by chloroform; the whole endoiilasm 



ri<ldled with nuclei. As yet without spores. 

 lb. Isolated spore X 1200. 

 2,1. Superficial epithelial layer; 6 healthy epithelial cells with nuclei, and 2 



separate strongly hypertrophied cells in which, very soon after infection, 



the nucleus is destroyed. 

 2, Ilfl. Myxosporidium fallen out of epithelial cell. Still without ectoplasm. 

 h. Young form, iree in urine with peculiar pseudopodioid motile ectoplasmic 



processes extruded and retracted on a slightly warm stage and many fat 



globules in the endoplasm. 

 2, Ilia. Pansporoblast formation ; a, small myxosporidium with bristle processes. 

 b. Sexanucleate pansporoblasts, which later form 2 triuucleate sporoblasts; 



in each sporoblast 2 nuclei form the capsules, the third the sporoplasm (iide 



Pfeifier). 

 8. Transverse section of tirinary bladder of pike, alcohol-hardened, celloidiu- 



imbedded, hsematoxylin-stained. 

 3a. Showing, from right to left, the external muscle layer, the internal muscle 



layer ciit transversely, the submucosa, the epithelium with infection in the 



superficial layers, and free brown-colored myxosporidia containing ha-ma- 



toidin and sporoblasts. X 80. 

 3fc. Portion of a. To the right the monstrously appearing myxosporidia and 



sporoblasts. X 400. 

 3c, Natural size of the bladder sectipii, 



