Fishes. 5127 



need merely state that it has been recognised in Denmark, Prussia, 

 Austria, various parts of Germany, France, and the British Isles. The 

 following are the chief synonyms by which it has been known : — 

 Saprolegnia ferox, Kutzing, Phyc. Gen.; Conferva ferox, Gruithuisen, 

 1821; Byssus aquaticus, O. F. Muller, Flor. Dan.; Vaucheria 

 aquatica, Lyngbye, Hydr. Dan. ; Hydronema, Car us, Act. Leopold. 

 1823; Saprolegnia Molluscorum and Achlya prolifera, N. V. Esenbeck; 

 Leptomitus clavatus, prolifer and ferox, Agardh, Syst. Alg. ; Lepto- 

 mitus Piscicola, Berkeley. It is not uncommonly found growing upon 

 the bodies of flies and other dead animal substances which have fallen 

 into water, especially in the summer months, and it is also well known 

 to occur upon the bodies of living fish, and to produce a most de- 

 structive form of epizootic disease amongst them — a perfect plague, of 

 extremely contagious nature. Thus, for example, M. Davaine has 

 described its baleful progress amongst the carp contained in a large 

 pond in France. Hannover and Stilling also notice its appearing 

 both amongst living and dead animals, growing " avec une extreme 

 rapidite," and producing in the former illness followed by death. 

 Unger likewise, in 1842, found sick Cyprini, with the plant fully 

 developed upon them, in a pond in the Gratz Botanic Gardens j and, 

 during the same year, he asserts that the fish in the environs of the 

 town were similarly affected, in so much that mouldy fish, as they were 

 commonly termed, were often to be met with exposed for sale in the 

 public markets ; in one large pond all the fish were exterminated by its 

 ravages, and in the reservoirs the thymale and trout also occasionally 

 suffered. He says, "It killed in about forty-eight hours; few re- 

 covered which were once attacked : it grew both on the body and the 

 fins; the fish lost their natural activity, sought the surface of the 

 water, and seemed fatigued; the plant extended from the mouth to 

 the vent, like a covering of velvet; the scales at the points attacked 

 loosened and fell off; the parts affected were evidently enlarged, 

 reddened, spotted with blood spots, and occasionally ulcerated ; the 

 fish appeared to move with pain, lay on their sides or back, and these 

 symptoms usually preceded death for only ten hours." 



To complete its history, I may mention that it has been met with 

 on the dead larvae of the land salamander in water (Cams), or dead 

 mollusca (Gruithuisen) ; on the wounded toes of the Triton punctatus 

 (Hannover) ; upon a wounded eel (Eg. St. Pierre) ; upon the eggs of 

 Limax agrestis (Laurent), and of Lynmaea stagnalis (Valentin) ; upon 

 both the ova and wounded body of Cyprinus Nasus (Valentin) ; upon 

 the eggs of the stickleback (M. Coste) ; and it is even stated that the 



