xiv DAYS AND NIGHTS OF SALMON FISHING 



largely as a result of the improvement of the Wye, 

 both rivers sharing the same estuary. Besides all 

 these fish plenty were left to reach the spawning 

 grounds and provide for future years. 



As I have said, our knowledge of the salmon has 

 increased, and this has helped an understanding of 

 fishery economics very much. Smolt-marking has 

 taught us a good deal, and so has fish-culture, but 

 the most striking modern development has been the 

 science of scale-reading, which has enabled us to 

 pronounce with a good deal of certainty as to the 

 age of the fish and the main outlines of their life 

 history. 



The study of fish-scales was first undertaken by a 

 Dutch naturalist, Leeuwenhoeck, in the seventeenth 

 century. He worked on the scales of carp, which are 

 less satisfactory than those of most fish, and his 

 discovery made no noise in the world. Indeed it 

 seems to have been practically forgotten (though I 

 have found traces of it in eighteenth-century litera- 

 ture on microscopy), until the close of the last 

 century when one or two men of science began to 

 apply the method to coarse fish (in Germany) and 

 to sea fish in this country. The pioneer of salmon 

 scale-reading was Mr. H. W. Johnston, who published 

 the first statement on the subject in The Field 

 newspaper in 1904. Since then very important 

 work has been done by Mr. J. Arthur Hutton and 

 others, but Mr. Johnston has the honour of intro- 

 ducing the new epoch. 



Scale-reading (aided by the confirmatory evidence 

 afforded by fish-marking) has upset some of the old 



