136 THE DOUBLE MIGRATION OF SALMON. 



although I am bound to mention that one gentleman who writes 

 on this subject accounts for the emptiness of the stomach by 

 asserting that salmon vomit at the moment of being taken. 

 The codfish again is frequently found with its stomach crowded ; 

 in fact, I have seen the stomach of a large cod which formed 

 quite a small museum, having a large variety of articles " on 

 board," as the fisherman said who caught it. 



It is supposed by some writers that salmon make two voyages 

 in each year to the sea, and this is quite possible, as we may 

 judge from data already given on this point ; but sometimes 

 the salmon, although it can swim withfgreat rapidity, takes many 

 weeks to accomplish its journey, because of the state of the river. 

 If there be not sufficient water to flood the course,the fish must 

 remain in various pools tUl the state of the water admits of their 

 proceeding on their journey either to or from the sea. The 

 salmon, like all other fish, is faithful to its old haimts ; and it is 

 known, in cases where more than one salmon-stream falls into the 

 same firth, that the fish of one stream will ■ not enter another, 

 and where the stream has various tributaries suitable for breeding 

 purposes, the fish breeding in a particular tributary invariably 

 return to it. 



But, iQ reference to the idea of a double visit to the salt 

 water, may we not ask— particularly as we have the dates of 

 marked fish for our guidance- — what a salmon that is known 

 to be only five weeks away on its sea visit does with itself the 

 rest of the year 1 A salmon, for instance, spawning about " the 

 den of Airlie," on the Isla, some way beyond Perth, has not to 

 make a very long journey before it reaches the salt water, and 

 travelling at a rapid rate would soon accomplish it ; but suppos- 

 ing the fish took thirty days for its passage there and back, and 

 allowing a period of four weeks for spawning and rest, there are 

 stiU many months of its annual life unaccounted for. It cannot 

 remain in the river forty-seven weeks, because it would become 

 so low in condition from the want of a proper supply of nourish- 

 ing food that it would die ; and it is this fact that has led to the 

 supposition of a double journey to the sea. The Eev. Dugald 

 Williamson, who wrote a pamphlet on this subject, entertains 

 no doubt about the double journey. "Salmon migrate twice in 

 the course of the year, and the instinct which drives them from 

 the sea in summer impels them to the sea in spring. Let the 

 vernal direction of the propensity be opposed, let a salmon be 

 seized as it descends and confined in a fresh-water pond or lake, 



