The MYXOSPORIDtA, OR PSOROSPERMS OF FISHES. 295 



Plate 15. 



Figs. 1-6. iiri/,ro/>o?»s? sj>. 41 (after Lieberkiibii; except 1). 



1. Two spores inclosed ia the pansporoblast meiiibraue (alter Butsclili. X %). 



X about 1050. 



2. Cyst from brancbiic of Gasteronteus aciilealiis ( X 1). 



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



4. Another cyst iu which spore formation has taken place ( X 1). X mv. 



5.' Another cyst (X 1). X 220. „ -. x, • •o/sra\ 



6a~c. " Diftereiit forms [? developmental stages] ot spores" of this species {X i^) 

 Fig. 7«-c. Mijxobolus sp, ii. . .. io-n 



7a. Transverse view of spore (after Lieberkiihn in Butschli. X t). X l^oO. 

 7&. Spore with valves separating, giving exit to sporoplasm (after LieberkuUn. 



7c. Sporoplasm undergoing amoeboid movenents (after Lieberktihu. X i)> 

 X 1350. 



Plate 16. 



Fio-s. 1-6. MyroUlKs miiUcri (after Biitschli. X 1, ex'cept fig. 1). 



" 1. Two branchial hunell* of a cyprinoid, one containing a conspicuous myxo- 

 sporidium. c. The cartilaginous rod supporting the lamella- ( X i). 

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

 clei." 

 .3</. Transverse view of spore. 

 3&. Transverse view of 2 separiited valves,^ 



4. An isolated small mysos]ioridium with its membrane* 



5. Nuclei of the myxosporidium. 



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



6ft. Sporoblast which Las segmented into the 2 protocysts and theprotospord- 



plasm. , ^ X , 1 • ,<. 



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



capsule formation. i u 



d, e. Later sta^^es of capsule formation. In e orientation of the capsules has 

 taken place. 



Pl.\te 17, 



FigR. 1-7. Myxoholus miiUeri (after Biitschli. X 1). . , i ^ 



1«. Vertical view ; showing capsules, sporoplasm, vacuole and poricoruual nuclei. 

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

 Ic. Vertical view, showing a common focus-appearance (ffocus-illusion), the 

 pericornual nuclei apparently attached to the posterior extremity of the 

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

 uole is invisible. 1 , . 'J ii 



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



filaments are extruded and the valves are beginning to gape apart. 



3. Vertical view of spore' with extruded filaments, sporoplasm, and "globules. 

 ia-d. "Abnormal" tailed spores; c, spore Avith 3 capsules. 



5. A separated valve, viewed transversely. 



6. Spore with filaments extruded by pressure. 



7a. Capsule not yet completely developed, with the filament extruded. 

 lb. A fully-developed capsule with extruded filament. 



Plate 18. 



Fias 1 2. Mijxobohisim-iforniis and j\l. eUipsoides (after Ba'ihinm. X 1). 



i. Section of splenic'artery of Tinea tinea, showing on the branches Malpighian 



corpuscles, most of them containing 3/i/.TO.s/)0)-i(i/rt. 

 2 The same, more highlv magnitied, showing well-developed bicapsulate torms 



(M. eUipmides) and pyriform unicapsulate or noncapsulate and degenerate 



forms (if. piriformis). 



