NATURAL mtroRY OF THE PAR. 191 



That par are never found in rivers, but such as 

 are immediately connected with the sea (all of 

 which more or less afford salmon), and never in 

 such parts of those rivers up which salmon cannot 

 ascend, is strictly true, and any instance to the 

 contrary, will, upon enquiry, turn out to be the 

 work of art or accident, not affecting the general 

 rule. But this does not establish the fact of any 

 connection between the two fish. . 



The power of closely observing fish in its ele- 

 ment is necessarily very limited ; much, therefore, 

 of their history must always depend on conclu- 

 sions and analogy. Now, assuming the par to be 

 a migratory fish and there is reason to believe it 

 is so all incongruity in this part of their history 

 is at once removed. Like all other migratory fish, 

 their travels must have a limit ; and a fall of water 

 that cannot be ascended by a salmon cannot pos- 

 sible be attained by these little fish : hence they 

 are never found except in rivers immediately con- 

 nected with the sea, and never found above falls, 

 weirs, &C;, up which salmon cannot ascend. The 

 only question seems to be at what period do the 

 par migrate, as they are certainly found in the 

 rivers during the whole year, although as certainly 

 not in equal quantities. Now, it is perfectly well 

 known that all fish immediately after spawning 

 become in a very unhealthy state, their bodies at 

 that period being infested with numerous water lice, 



