528 REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



our rivers, it may be of advantage that I should meutiou "what I ob- 

 served ill a small river at the head of Castrie's Bay, in Siberia. I found 

 the river rather low, but with plenty of clear running water. But what 

 astonished me was to see thousands of salmon in all stages of disease 

 and death, some darting away, but soon stoi)ping to rub the side on 

 the bottom or on a rock ; others were constantly rubbing, others unable 

 to rub. In those last cases large sores, from the size of a shilling to 

 that of a half-crown, of a most tilthy appearance, were always present. 

 Fish in which the scales had been rubbed off would try to get out of my 

 way, but I could kill them with a stick ; those with the skin gone would 

 rub themselves against my trousers." 



Supposing this salmon from the Nith had been to sea, and had while 

 there got rid of the greater part of the fungus with which it was affected, 

 it had returned to the river in such a mutilated condition, and with un- 

 healed sores of such a nature as in all likelihood would have ultimately 

 proved fatal. Besides, the fact that the fungus was not killed by the 

 salt water, but was found in a highl3* vigorous condition on the parts to 

 which it still adhered, gives but small hope of any permanent benefit to 

 diseased fish from a visit to the sea. 



The fungus belongs to SaproJegnke, a natural order of doubtful affin- 

 ity, said to have the habits of molds and fructification algse. This order 

 consists of the genera SaproJegnia and AcliJya, which are great enemies of 

 fish and other animals preserved in aquaria. 



The filaments of the fungus arise free from the outer surface of the 

 epidermic layers of the fish, having neither branches nor articulations. 

 They are tubes, the walls of which are perfectly translucent, and in 

 their interior, at irregular intervals, are small groups of fine granular 

 matter. 



The majority of the filaments are spear-shaped at their upper termi- 

 nations, and appear to be barren. 



The prolific filaments, on the contrary, enlarge at their upper extremi- 

 ties, and form elongated club-shaped chambers, in which granular mat- 

 ter gathers. In the midst of this granular matter small round bodies 

 ai^pear, and, those enlarging, gradually develop into spores. The pro- 

 lific filaments apparently contain more granular matter, and are of greater 

 caliber than the other filaments. They are e\adently destined from the 

 first to be the propagating media. 



The spores escape by an opening in the summit of the chamber. This 

 aperture is not an original oi^ening ; it is produced in a somewhat remark- 

 able manner. So long as the spores are unripe and unfit for expulsion, 

 a slender continuation of the filament projects from the apex of the 

 chamber in a manner similar to the neck of a bottle. At the point at 

 which this joins the spore sac there is a slight contraction, which goes 

 on gradually increasing in depth.' Ultimately, when the spores are 

 fully matured, it drops off, and the aperture is formed. The filaments 

 forming the mycelium of the x>lant are tortuous and branched j they 



