214 BUI^IvETlN OF THE BUREAU OF FISHERIES. 



Fig. 26. A sporocyst of M. musculi from a smear of diseased integument of the mouth and head 

 in front of the eyes. Elsewhere the sporocysts have less cytoplasm. It is the only one encountered 

 in this condition. The failure of the nuclei to take the stain is characteristic. The myxospore is 

 immature, being less slender than older myxospores. The details of the polar capsules are very trans- 

 parent and stain dark blue, while the spore wall is a very pale blue. The vacuole and sporoplasm are 

 prominent, but the nuclei of the spore can not be clearly discerned. Sporocyst, ly.S/t by 23.S/1; spore, 

 14. 8/1 by 7.4U; polar capsule, 7.4U by 2.2/1. There are 13-14 spirals in the filament. Fixation: Absolute 

 alcohol, ether, corrosive sublimate, acetic acid. Stain: Mayer's haraatein, methylene blue, orange G., 

 eosin. (X2000.) 



Fig. 27. A sporoblast of M. musculi from a fresh smear of degenerated muscle taken from a deep 

 cavity (the same as fig. 20). Easily distinguished from tissue cells by the three nuclei. Protoplasm 

 contains much coarsely granular matter. (Drawn free-hand, not to scale.) 



Fig. 28. M}Tcospore from the same slide as figtu'e 26. The mature spore, when compared with that 

 in the pansporoblast, is longer and more pointed at the polar end. The vacuole is probably an iodi- 

 nophilous structure. The coiled filaments make 11 to 12 turns. The polar capsule wall is visible, but 

 the spore wall can not be clearly seen. The valves and sutures are also indistinguishable. While there 

 are as many as 12 blue and green bodies present, one can not be sure that all of them are nuclei. Seven 

 or eight bodies are moderately conspicuous. Two lie in the wall of the polar capsules and are doubtless 

 the capsule nuclei. 14.8/1 by 6.2/1. (X2000.) 



Fig. 29. A mjTcospore of M. musculi from large sores on each side of the tail of a Fundulus heteroclitus, 

 caudal fin entirely gone. Fixed in absolute alcohol and ether, stained with methylene blue. Six 

 unstained nuclei in the sporoplasm and one large vacuole. Filament discharged. Spore, 7.4,11 by 16.4/1. 

 Polar capsule, 2.2/1 by 7.4/1. (X2000. ) 



Fig. 30. Diagram of the cross section of a fresh myxospore of M. musculi as if seen from the end. 

 The specimen was lying so as to present the edge of the valves to view. It is obviously flattened. The 

 polar capsules also appeared to be, but one can not be certain about this. The sutures are straight and 

 symmetrical. Fixation: Alcohol, ether, formalin; Giemsa stain. (This drawing not made to scale.) 



[Figures 31 to 34 are all from the same smear preparation of diseased muscle from a dead fish, being 

 one of those taken from jar no. i (see pp. 195, 196).] 



Fig. 31. Pansporoblast of Chloromyxum funduli embedded in a degenerated muscle fiber. The 

 contained myxospore has taken up the stain, but the protoplasm of the pansporoblast is absolutely 

 devoid of visible structture. Note the even contour of the characteristic lobose pseudopodia. 15.2/1 by 

 12/1. (X2000.) 



Fig. 32. One of a group consisting of free young myxospores of C. funduli. Like the matiu"e 

 myxospores, they stain readily, but their nuclei are not differentiated. They are, as a rule, not quite 

 so irregular, but the pseudopodia are always small and angular. Note the contrast between these and 

 the pansporoblasts. 3.7/1 by 4. 5/1. (X2000.) 



Fig. ;j;i. Myxospore of C. funduli. The outline is approximately circular. The sporoplasm is 

 homogeneous but dense aroimd the foiu' polar capsules, doubtless because of the greater thickness at 

 this point. The four nuclei are always associated with the polar capsules, hence are doubtless capsule 

 nuclei. Diameter, 8.9/1. (X2000.) 



Fig. 34. Myxospore of C. funduli seen from the side. Note the sporoplasm is not much denser 

 about the polar capsules. The sporoplasm tapers to a blimt apex. In many it is more pointed. The 

 polar capsules have long, curved, tapering necks with the large ends far apart. The capsule nuclei 

 alone stain. 8.2/1 by 6.7/1. (X2000.) 



Fig. 35. A fresh sporoblast of M. musculi from the same slide as figures 20 and 27. The cyto- 

 plasm is rich in granules. The nucleus is very large and has a conspicuous karyosome. (Not drawn 

 to scale.) 



Fig. 36. An isolated epidermal cell derived from a mass near the margin of an advanced ulcer, 

 most of which have numerous unstained bodies like those in the muscle fibers (fig. 12, pi. xx). From 

 sections. The epidermal cell is not typical in appearance, but the unstained bodies are, and are iden- 

 tical to those in the adjacent slightly atrophied epidermis. (X2000.) 



