THE LAW AS '1Q. -SALMON-FISHING 225 



is good evidence to prove that the Crown was en- 

 titled to make such grant to confirm a several fishery 

 which existed before the time of legal memory. If 

 the right to a several fishery is once proved, no act on 

 the part of the public can divest the owner of that right 

 or transfer it to the public. The right may be shortly 

 described as riparian, since it attaches to the owners of 

 the soil adjoining the river on either bank, or to persons 

 deriving their title from such owners. Where the oppo- 

 site banks are in different ownership, the right extends 

 ' ad medium filumj i.e. to a line drawn over the centre of 

 the main channel of the river. This right, as has been 

 said, attaches to the soil, and so, should the river 

 change its course, the owner of a several fishery in 

 the old channel cannot claim a right in the new 

 channel, if it has left his lands. With regard to the 

 right extending only ' ad medium Jilumj an obvious 

 difficulty suggests itself, in cases where the water is at 

 all narrow and the catch is in a single channel, which 

 renders it impossible effectively to fish with rod or 

 net without passing the line in mid-stream. In strict 

 law, to do so is an encroachment ; but, as a matter of 

 custom, this difficulty is adjusted in practice by 

 arrangement between the adverse owners. 



In England a several fishery can be granted or 

 leased only by deed, in order to be effective. This 



