296 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
PLATE 19. 
Fig. 1. Myxobolus bicostatus (after Lieberkiihn in Biitschli. x 3). Vertical view of 
spore showing the 2 oblique ridges on the shell, the capsules, and the 
sporoplasm. 
Figs. 2-8. Myxobolus ellipsoides. 
2,3. Pfeiffer’s copies of figs. la, 1b of plate 20 (x 1). 
4. Mesenteric artery of Tincatinca 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 (hxematoidin-colored) gran- 
ular matter (after Balbiani.  X 1). 
5. Section of diseased air bladder of 7. tinca, showing spores and, at the left-hand 
margin, the internal epithelial surface of the air bladder. Borax carmine, 
gentian violet (after Thélohan. X1). 
6. Section of cyst of branchiz of T. tinca; 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 Thélohan. x 1). 
7. Transverse section of air bladder; carmine, celloidin (after Pfeiffer. x 1). 
x 100. 
8. Portion of fig.7 (after Pfeiffer. x 1). Xx 400. On the wall of the cyst the 
younger, still uninuclear, parasites; to the right trinucleate sporoblasts. 
PLATE 20. 
Figs. 1-4. Myxobolus ellipsoides. ; 
la-c. Myxosporidium and cyst from fins of Tinca tinca, with spores in course of 
development (after Balbiani. x 1). 
la. Small myxosporidium containing only nuclei. 
1b. More advanced stage. 
le. Large encysted myxosporidium containing numerous spores, mostly mature. 
2a-c. Three stages in spore formation, showing paired development of spores in 
amass of homogeneous plasma, and the spores contained at maturity in a 
vesicle (after Balbiani. x 3). 
3a-c. Spores from air bladder of T. tincashowing ribbons (after Balbiani.  #). 
3a, b. Spores united by the ribbons, the sporoplasm rolled into a ball, and the 
“accessory ” capsules. 
3c. Isolated spore with extended ribbons; capsules empty; sporoplasm in a ball. 
4a-e. Spores from the air bladder of 7. tinca, showing different stages of devel- 
opment of the nuclei; carmine, gentian violet (after Thélohan. X 1). 
4a. Spore with 1 nucleus. 
4b. Spore with 2 nuclei. 
4c. Spore with 3 nuclei. 
Ad, e. Spores with 4 nuclei. 
PLATE 21. 
Figs. 1,2. Myxobolus ellipsoides. 
la-h. (After Balbiani. x 3.) 
la. Vertical view of spore, showing pericornual nuclei and anteriorly a 
“‘olobule.” 
1b. 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 capsules with filaments extruded, pericornual 
nuclei, anteriorly a ‘‘globule,” and posteriorly the sporoplasm (? contracted 
under the action of reagents). 
1d. Spore in vertical view, showing ribbons, and sporoplasm in act of exit. 
le. Capsule with filament coiled. 
1f-h. Different degrees of extrusion of filament. 
2a-e. Sporoplasm after exit, showing changes of form (after Balbiani. x $). 
n, “nucleus” [ ? vacuole]. 
Fig. 3. “Degenerate processes of the*spores of Tinca tinca with 3, with 2 approxi- 
mated, with 1 capsule, with candiform drawing out of one pole, with 
approximation to the sarcosporidian germs. The same are found in the gall 
bladder of the tench and in aneurisms on the splenic artery” (after Pfeiffer. 
xeb) ex C00: 
d. Myxobolus ellipsoides (apparently ; remainder indeterminate). 
Fig. 4a-b. Myxobolus ellipsoides?? ‘Spores inclosed in a cell [?pansporoblast] mem- 
brane becoming stained at the moment of birth, with eosin” (after and 
jide Pieter. ><). = <t50: 
Fig. 5. Myxobolus ellipsoides. ‘Mature spore, with band-like connection of shell, and 
with vacuole at place of expelled germ” (after and fide Pfeiffer. x1). x 750. 
