250 THE RIVER-SIDE NATURALIST. 



absence from the nets almost seeming to point out the 

 probability that they are not present/' 



Mr. Young states that he has often marked grilse, and 

 that they have returned from the sea as salmon. A grilse 

 kelt of 2 Ibs. weight was marked on March 31, 1858, and 

 was recaptured on August 2 of the same year as a salmon 

 of 8 Ibs. 



Mr. Johnstone (evidence before Committee of the House 

 of Commons), in describing the two fish, salmon and grilse, 

 says : " The grilse is a much less fish in general, it is 

 much smaller at the tail in proportion, and it has a much 

 more swallow tail, much more forked ; it is smaller at the 

 head, sharper at the point of the nose, and generally the 

 grilse is more bright in the scale than the salmon." 



Day says : " Doubtless there is a difference in the ap- 

 pearance of the small salmon and a grilse of the same size, 

 but such is probably due to the former, from some cause, 

 not having got into condition, and so lost a season. That 

 grilse frequently reascend rivers at irregular periods has 

 been constantly observed, while they have also been en- 

 tirely absent for a whole season, as in 1867." 



It has also been observed that the grilse has more spots 

 below the median line, and that the scales are smaller and 

 more easily rubbed off, than the salmon. 



Mr. Scrope (" Days and Nights of Salmon-Fishing") 

 gives a table showing the increase in weight of grilse after 

 returning from the sea as salmon, taken from an experi- 

 ment made by a tacksman on the Duke of Sutherland's 

 salmon-fishery on the river Shin. In the course of 

 February and March 1841 he took a considerable number 

 of grilse or gilses and marked them with a wire in various 

 places sufficiently efficacious to be again recognised. Of 

 these, ten were retaken in the course of the months of 

 June and July following, by which time they had assumed 

 the size and all the distinctive marks of the genuine salmon. 

 It shows also how rapid the growth of the grilse is in his 

 process of becoming a salmon : 



