280 REPORT OF THE COMMISSIONER OP FISH AND FISHERIES. 



branous character of the ectoplasm. No traces of change of form or 

 place were seen. 



Spore formation. — Beginning with individnals scarcely one-tenth the 

 maximum size, the number of spores being then, however, relatively 

 as well as absolutely less; number increasing jmH fjassw with growth, 

 individuals of equal size not necessarily showing, however, equal num- 

 bers. In specimens largest and most rich in spores the latter show 

 themselves scattered over the surface at very short intervals, while on 

 the borders they form a com2)act zone visible macroscox)ically as a white 

 ring. 



Pansporoblast?: Myxosporidia of various ages tolerably frequently 

 show a spore-fonndatiou [Sporenanlage] in the form of a smaller, more 

 elongate, and only delicately outlined oval, containing two small pale 

 perfectly round capsules (somewhat removed fi'om the poles), which 

 inclose a tolerably large dark biconcave-ended cylindrical rest-body 

 [Restlcorper). The delicately outlined oval contracts its bulk, its out- 

 line clears up, and the shell and capsules become tliicker and very i)romi- 

 nent. Valve-connection takes place through a process of the shell, and 

 the spore becomes more ventricose. 



Spore. — Lying outside the vesicles, always arranged in pairs, the lat- 

 ter rather irregularly scattered under and only loosely connected with 

 the ectoplasm, concentrated in greatest numbers along the borders, 

 forming a white ring. Length of mature spore, 12 to 14//; breadth, 

 9 to 10 /<; regularly oval, with blunt ends; spore showing no independ- 

 ent movements except filament extrusion. 



Shell rather thick and firm, indistinctly and finely transversely striate, 

 possessing the usual resistance to chemical reagents; bivalve, the valve- 

 junction plane oblique (like the diagonal of a rectangle), inclined about 

 45° to the "equatorial" [transverse?] plane. This condition doubtless 

 stands, Lutz says, in connection with the position of the capsules at 

 either end, one valve lodging each. Around the border of each valve 

 is placed, hoop-like, a little elastic rod, plainly projecting in profile, 

 rebounding, when treated with potassium liydrate, in the form of a more 

 or less extended baud, the valves thereby becoming loosened, a piece 

 often being torn away. Lutz remarks that these observations agree 

 with Balbiani's (p. 223). Lutz, however, never saw any connection of 

 spore-pairs through the medium of the loosened bands. 



Capsules 2, separated, 1 at each end, subglobular-pyriform, slightly 

 sharper anteriorly, glittering stronglj^ in water or in bile, only slightly 

 so in glycerin and other retractile fluids; size diniinished by extrusion 

 of filaments, walls plainly double contoured. Filaments difficultly per- 

 ceivable when fully coiled, plainly visible when half uncoiled; extrusion 

 frequent in bile, not so common in water; extrusion also producible by 

 various reagents, most certainly by potassium hydrate. Length, 4 to 5 

 times that of the spore-length. 



Sporoplasm transparent, first becoming plainly visible after the action 



