296 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Plate 19. 



Fig. 1. Myxoholus Mcostatus (after Lieberkiihn in Biitschli. X f). Vertical view of 

 spore showing the 2 oblique ridges on the shell, the capsules, and the 

 sporoplasm. 



Figs. 2-8. 3Iyxoholu8 ellipsoides. 



2, 3. Pfeiffer's copies of figs, la, 16 of plate 20 (X 1). 



4. Mesenteric artery of Tinea tinea with sessile or pedunculate cysts developed 



at the expense of the connective tissue coat of the vessel. Cyst contents 

 myxosporidia, alone or with imbedded brown (hsematoidin-colored) gran- 

 ular matter (after Balbiani. X 1). 



5. Section of diseased air bladder of T. tinea, showing spores and, at the left-hand 



margin, the internal epithelial surface of the air bladder. Borax carmine, 

 gentian violet Rafter Th^lohan. Xl). 



6. Section of cyst of branchite of T. tinea; showing in order, from above down- 



ward, the branchial epithelium, cyst membrane, myxoplasm, spores, and the 

 nuclei of the last. Picro-carmine and gentian violet (after Th^lohan. X 1). 



7. Transverse section of air bladder; carmine, celloidin (after Pfeiflter. X 1). 



X 100. 



8. Portion of fig. 7 (after Pfeiflfer. x 1). X 400. On the wall of the cyst the 



younger, still uninuclear, parasites; to the right trinucleate sporoblasts. 



Plate 20. 



Figs. 1-4. Myxoiolus eUipsoides. 



la-c. Myxosporidium and cyst from fins of Tinea tinea, with spores in course of 

 development (after Balbiani. X 1). 



la. Small myxosporidium containing only nuclei. 



lb. More advanced stage. 



Ic. Large encysted myxosporidium containing numerous spores, mostly mature. 



2a-c. Three stages in spore formation, showing paired development of spores in 

 a mass of homogeneous plasma, and the spores contained at maturity in a 

 vesicle (after Balbiani. X i). 



3a-c. Spores from air bladder of T. <i?!ca showing ribbons (after Balbiani. X f). 



3a, i. Spores united by the ribbons, the sporoplasm rolled into a ball, and the 

 "accessory" capsules. 



3e. Isolated spore with extended ribbons; capsules empty; sporoplasm in a ball. 



4a-^. Spores from the air bladder of T. tinea, showing different stages of devel- 

 opment of the nuclei ; carmine, gentian violet (after Th61ohan. X 1). 



4a. Spore with 1 nucleus. 



4&. Spore with 2 nuclei. 



4c. Spore with 3 nuclei. 



id, e. Spores with 4 nuclei. 



Plate 21. 



Figs. 1,2. Myxoholus ellipsoides. 



la-h. (After Balbiani. X ?.) 



la. Vertical view of spore, showing pericornual nuclei and anteriorly a 

 "globule." 



1&. Transverse view, showing the equal convexity of the valves and the equality 

 of the two ends of the spore. 



le. Vertical view of spore, showing ca])sules with filaments extruded, pericornual 

 nuclei, anteriorly a "globule," and posteriorly the sporoplasm (? contracted 

 under the action of reagents). 



Id. Spore in vertical view, showing ribbons, and sporoplasm in act of exit. 



le. Capsule with filament coiled. 



l/-7(. Different degrees of extrusion of filament. 



2a-e. Sporoplasm after exit, showing changes of form (after Balbiani. X f ). 

 n, "nucleus" [ ? vacuole]. 

 Fig. 3. "Degenerate processes of the spores of 77nea tinea with 3, with 2 approxi- 

 mated, with 1 capsule, with candiform drawing out of one pole, with 

 approximation to the sarcosporidiau germs. The same are found in the gall 

 bladder ot the tench and in aneurisms on the splenic artery " ( after Pf'eiii'er. 

 X 1 ). X 1000. 



' d. Myxoholns ellipsoides (apparently; remainder indeterminate). 

 Fig. 4a-&. Myxoholus ellipsoidesf? "Spores inclosed in a cell [fpansporoblast] mem- 

 brane becoming stained at the moment of birth, with eosin" (after and 

 .^rfe Pfeiffer. X 1). X 750. 

 Fig. 5. Myxoholus ellipsoides. "Mature spore, with band-like connection of shell, and 

 with vacuole at place of expelled germ" (after and/de Pfeiffer. X 1). X 750. 



