INTR OD UCTION 5 



respect for local varieties has caused that veteran ichthyologist 

 unduly to multiply species. But I have kept the purely 

 scientific part of the history as subordinate as possible, retaining 

 the classification merely as a clue, avoiding anatomical details, 

 which I am wholly unable to give from original research, 

 and merely indicating the number of fin-rays in each fish, and 

 the arrangement of the teeth, as a simple aid to identification. 



Regarding the illustrations, I desire to acknowledge with 

 gratitude the help I have received from those, too numerous 

 to mention by name, who have kindly sent photographs for 

 reproduction. One great difficulty has had to be encountered 

 by Miss Seth, the artist who has prepared coloured reproductions 

 of these photographs — namely, the rapid changes which take 

 place in nearly all fish immediately after death. For instance, 

 in almost every coloured representation that I have ever seen, 

 the iris is coloured red or orange. Now the iris of a living or 

 freshly killed salmon is the palest yellow, dusted with black ; 

 it is only when decomposition has begun that the eye becomes 

 shot with blood ; and the portrait of a salmon can seldom be 

 taken until that process has set in. The delicate skin tints of 

 trout, minnows, sticklebacks, and many other fish are equally 

 evanescent, and tax to the utmost the artist's ingenuity and 

 rapidity of execution. 



