THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 297 



Plate 22. 



Figs. 1-3. Myxoholns elUpsoides ? (after Pfeiifer. X 1). 



1, 2. Spores from the gall bladder of Tinea Uiica. 



3. Spores from the air Ijladder of T. thica. 

 Fig. 4o, b. Mysobohis sp. 50 (after Leuckart. X 1). 



4n. Vertical view of sjjore. 



46. Transverse view of spore. 

 Figs. 5,6. Myxohohtu sp. 51 (alter Pfeiffer. X 1). 



5. Myxosporidian infe<tion of Barhus barhus. 



6. Tumors of mn.scle. 



Plate 23. 



Figs. 1-2. Myxobolus sp. 51. Myxosporidian infection of Barhus harbus (after Pfeif- 

 fer. X 1). 



1. From a photomicrograph. 



2. Infection of the muscle cells and the interfibrillav connective tissue. 



2a. General innnigration of myxosporidian spores into muscle with degenera- 

 tion of the neighboring parts of the mnscle and with beginning of incapsiil- 

 ing on the part of the host. 



26. Split spores. To the left, the exit of the sporoplasm; to the right, empty 

 shells undergoing solution. 



2c. The myxosporidium (sporoplasm) in the first stages of growth; on the right 

 the same, after hardening and hiematoxylin. 



2d. Nest growth-stage of myxosporidium; adhesion of individuals to a "sorus." 



Plate 24. 



Figs. 1,2. Myxobolus sp. 51 (after Pfeiffer. x 1). 



la-/). Sections of muscles of Barhus harbus, showing myxosporidian cysts, spores, 



etc. For details, sea Hibliography, Lxxii. p. 127. 

 2a. A large muscle ceil of abdominal wall beaded by myxosporidian cysts; the 



transverse striation and the substance of the muscle has disappeared. Size 



of cysts, variable; contents, spores. X 100. 

 2b. Fragment of muscle cell. Showing 5 spore cysts. Between the upper and 



the next to the upper cysts lie 7 spores in the muscle cell (supplementary 



immigration ?). X 100. 

 2c. Fragment of another muscle cell with 6 cysts. The upper 2 with maturt 



spores; between them 6 spores, whose capsules lack the oblique striatioi 



(filaments extruded ?). The third cyst with the contents divided into pan. 



sporoblasts, in which as yet no spores are visible. The fourth and fifth 



(from above) showing nuclei, surrounding dancing grannies, and a hyalint 



ectoplasm; both are inclosed in a mesh of the original muscle cell. X 400 

 2d. Myxosporidium free in the intertibrillar connective tissue, x 750. 

 2c. Mature spore. X 750. 



Plate 25. 



Figs 1-6. Myxobnhis sp. 51. 



1 a-h. Group of spores, most of them viewed vertically (after Meguin. X f). 



1&. Spore with filaments extruded. 



Ic. Isolated capsules. 



Id. Same, with extruded tilamont. 



Ic. Spores viewed transversely. 



If-h. Spores apparently imbedded in the myxosporidium. 



2. Showing a, vertical, and b, transverse views of spore, and c, a transversa ciew 



of a separated valve (after Ludwig, X 1). X 2000. 



3. Spore viewed vertically (after Pfeiffer. X 1). 



4. Isolated myxosporidium, showing spore formation (after Pfeiffer, Y 1). 



5. Spores and the extruded amoeboid sporoplasm (after Pfeiffer. X 1). 



5a. Vertical view, showing one capsule with filament extruded, sporoplasm, 



vacuole, and 3 reft-ingent bodies of undetermined significance. 

 56. Transverse view of spore showing ridge. 

 5c. Sporoplasm, after exit, in various locomotive stages. 



6. Spores, showing filaments extruded, and sporoplasm in the act of, and after 



exit, apparently also the vacuole (after Pfeiffer. X 1). X J/jO. 



