Synopsis

Exposed, and the ifins are eaten away, and become ragged. Very often one or both gill-covers become partially glued down to the shoulder, and the gill-openings obstructed, but I have never yet been able to meet with any sign of disease on the gills themselves. This is contrary to common belief, but I can only say that such is my experience. On the other hand, the disease frequently invades the cavity of the mouth, and often more or less destroys the mem- branous veil which lies behind the teeth, and plays a curious part in respiration. Thus, although, so far as I have been able to observe, the respiratory organs are not directly attacked, the performance of the respiratory function may be very seriously obstructed.