^2 THE SEA-TROUT 



better than refer the reader to his clear discussion of the subject in the 

 chapter on " Grilse " in his book " The Life of the Salmon." As Mr. 

 Calderwood's point of view, in any debatable question, is ever that of 

 the open-minded inquirer after truth, all the more weight may be 

 allowed to his conclusion : — " In my view the prevailing characteristics 

 of the group of fishes to which the Salmon belongs are those of marine 

 fish of plastic nature, capable of much local variation both of appearance 

 and habit, many of which enter fresh water freely." Dr. Day was of 

 a like opinion. 



Anglers would appear to prefer for the Salmonida a fresh-water 

 origin. Sir Herbert Maxwell discusses the question in his book on 

 " Salmon and Sea-Trout " (in " The Angler's Library " series), and 

 arrives at a fresh-water conclusion; while the late Mr. Hamish Stuart 

 in another connection recognised a fact which " seems to assign to the 

 common ancestor of the Sabnonidcp. a fresh-water origin." 



Presumably discovery made of the " common ancestor " and its 

 habitat will finally settle this matter, but that discovery is not yet. 

 That science is not without hopes may be inferred from this extract 

 from a letter which Dr. A. Smith Woodward, Geologist in the British 

 Museum, has written to my friend Dr. J. W. Gregory, Professor of 

 Geology in the University of Glasgow, the purport of which has been 

 kindly placed at my disposal. Dr. Smith Woodward writes : — " Prac- 

 tically nothing is known of the ancestry of the Salmonkla;. A few- 

 typical remains are found in the fresh water Tertiaries of the Continent 

 (see references in Catal, Foss, Fishes, B.M., pt. iv), but they merely 

 show how old is the family. Of all the modern fresh-water fishes we 

 lack ancestors connecting them with the marine forms. We shall find 

 them some day." I have no authority to rank Dr. Smith Woodward 

 either as an exponent or as an opponent of the " marine origin " theorv, 

 but his letter suggests that something at least mav be said for those 

 who take the view of a fresh-water origin. 



