THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 295 



PX.ATE 15. 



Figs. 1-6. Myxoboliis? sp. 11 (til'ter LieberkiibB; except 1). 



1. Two spores inclosed in the pansporoblast membrane (after Biitschli. X |). 



X about 1050. 



2. Cyst from brancbia', of Gasterosteus actileatus (X 1). 



3. Free spores from cyst of fig. 2. (X f.) X 675. 



4. Another cyst in which spore formation has taken place ( X 1). X 330. 



5. Another cyst (X 1). X 220. 



6a-c. " Different forms [ ? developmental stages] of spores " of this species ( X f .) 

 Fig. 7a-c. Mjjxoholuii sp. 44. 



7a. Transverse view of spore (after Lieberkiihu in Biitschli. X |). X 1350. 

 75. Spore with valves separating, giving exit to sporoplasm (after Lieberkiihn. 



X 3). X 1350. 

 7c. Sporoplasm undergoing amoeboid moven-ents (after Lieberkiihn. X 1). 



X 1350. 



Plate 16. 



Figs. 1-6. Mi/xohohis milUeri (after Biitschli. X 1, cxrept fig. 1). 



1. Two lirauchial lainelhe of a cypriuoid, one containing a conspicuous myxo- 



sporidinm. c. Tbe cartilaginous rod supporting tbe lamella (x 'i). 



2. A portion of the membrane of fig. 4, more strongly magnified, showing "nu- 



clei." 

 'Sa. Transverse view of spore. 

 oh. Transverse view of 2 separ ited valves. 



4. An isolated small myxosiiorldium with its membrane. 



5. Nuc lei of the myxosporidium. 



fi. A series showing the developmental stages of the spore. 



6a. Sporoblast which Las segmented into the 2 protocysts and the jirotosporo- 



plasm. 

 b-c. The segments have oriented themselves; the protocysts show beginning 



ca]»sult' <ornu\tion. 

 d, e. Later stages of capsule formation. In e orientation of the capsules has 

 taken place. 



Plate 17. 



Figs. 1-7. Mijxohohis m'uUeri (after Biitschli. X 1). 



Irt. Vertical view ; showing capsules, sporoplasm, vacuole and pcricornual nuclei. 



\b. Vertical view; showing capsules, "globules," sporoplasm, and vacuole. 



Ic. Vertical view, showing a common focns-appenrance ( ffocus-iilusion), the 

 pericornual nuclei apparently attached to the posterior extremity of tlie 

 capsules. Biitschli says the sporoplasm is " contracted " and hence the vac- 

 uole is invisible. 



2. Transverse view of spore after action of concentrated sulphuric acid; the 



lilaments are extruded and the valves are beginning to gape ai)art. 



3. ^'ertical view of si)orc with extruded filaments, sporoplasm, and "globules." 

 A^a-d. "Abnormal" tailed spores; c, spore with 3 capsules. 



5. A separated valve, viewed transversely. 



6. Spore with filaments extruded by pressure. 



la. Capsule not yet completely developed, with the filament extruded. 

 Ih. A fiilly-deveioped capsule with extruded filament. 



Plate 18. 



Figs. 1, 2. Myxohnlus piriformis and M. eUipsoides (after Balbiani. X 1). 



1. Section of splenic artery of Tinea tinea, sliowing on the branches Malpighian 



corpuscles, nu)st of them containing Murosporidia. 



2. Tlie same, more highly m.ignilicd, showing will-devcloped bicai)snlate forma 



(At: eUip^oides) and pyriform unicapsulate or uoncaj)sulato and degeneriite 

 forms {M. piri/orniia). 



