INTRODUCTORY 



15 



orcadensis, though whether it is claimed as a migratory or non-migratory 

 trout is not clear. 



Now it long ago occurred to me that there was a welter of confusion 

 in all this differentiation which might possibly be accounted for by the 

 fact that scientific systematists, who had no great practical knowledge 

 of the actual ways of fish, had lent too credulous an ear to local popular 

 beliefs in exceptional types, while, on the other hand, practical men 

 who had no scientific training at all had acquired the habit of claiming 

 as the attributes of some new species what were really after all only 

 superficial differences in some known species. 



The somewhat specialised nature of my work with the Loch Lomond 

 Angling Improvement Association, carried on for over fifteen years, 

 has made it possible for me to appreciate the efforts of those who have 

 made simplication, and not complication, of our subject their aim and 



study. 



Some few writers had already conceived of there being only one 

 species of our British trout, and perhaps Dr. Francis Day, the author 

 of " British and Irish Salmonidcs'' published in 1887, is the most 

 representative of those whose views tended in that direction. In his 

 preface he says : — " It has been increasingly evident to me for some 

 years that one of the main reasons militating against the successful 

 cultivation of trout (and possibly char) in this kingdom by riparian 

 proprietors, has been the confusion into which these forms have been 

 thrown by naturalists, who, in order to give greater accuracy to their 

 descriptive treatises on Museum specimens, have subdivided them into 

 many species. The consequence of this has been, that fish-culturists 

 who have accepted the statements made, have been constantly attempt- 

 ing to introduce new species into their waters in order to improve the 

 native race. For the zoologists who have been most active in raising 

 local varieties to specific rank have been compelled to admit that they 

 all very commonly interbreed, but that the young revert to one of the 



