RAPID GROWTH OF SALMON. 207 



stunted by deprivation of their natural food; 

 and their natural constitution would be so much 

 impaired, that, in all probability, they would pre- 

 maturely die from inanition, or from other cause of 

 early decay. If they did not, I conjecture they 

 would become in time a distinct species offish, or 

 the progenitors of some distinct species ; very likely 

 some nondescript sort of fresh-water trout. 



Salmon, if they live long, cannot grow in after 

 years as fast as they grew during the earlier pe- 

 riod, particularly the grilse stage of their existence, 

 when they frequently increase their size eight-fold 

 in a sea-sojourn of two months. A salmon weigh- 

 ing, when caught in its descent to the sea, 10 lbs. 

 has been retaken on its return after a sojourn of 

 thirty-eight days on its salt-water feeding-ground, 

 and when recaptured it weighed 21^ lbs. This 

 instance of the wonderfully rapid growth of salmon 

 occurred in the Tay near Dunkeld, and was ve- 

 rified by the present Duke of Athol.* Now, if 



* In a private letter, dated May 11. 1845, his Grace, 

 then Lord Glenlyon, writes, " I have received the ticket 

 [a zinc one that had been attached to a foul fish or " kelt," 

 caught by his Grace as it descended to the sea for the pur- 

 pose of ascertaining the duration of its sojourn, and its rate 

 of growth in salt-water.] ISTo. 129. from Mr. Wilson, and 

 on referring to my salmon journal, I find that I caught this 



