INTRODUCTION. 21 



have been spared, however, to make them complete. 

 Fishermen have been employed for every river, to 

 ransack its waters by hooks and nets for possible 

 treasures, and to send the results of their labours for 

 examination and identification. 



Fish, as a rule, in any stage of their existence, 

 are easily identified, except in some genera, where the 

 alteration before natural growth is complete is very 

 great and the immature fish is so unlike its parents 

 that another specific name has been actually con- 

 ferred upon it ; while sometimes, even, the immature 

 fish has been placed under another generic name. 



Yet the difficulty that many experienced fishermen 

 have in correctly naming their captures shows how 

 needful it is to be careful in this respect. The 

 resemblance of allied species, such as the Rudd and 

 the Roach, cause frequent mistakes. This similarity 

 is so strong that I rarely meet with even an 

 experienced angler who can give the distinguishing 

 characters of these common fish. Judging by the 

 notices in the various journals, few among our edu- 

 cated fishermen even appear to differentiate the 

 various species they capture. It may constantly be 

 seen recorded that so many Bream or Roach have been 

 taken records perfectly useless to the naturalist, and, 

 from their imperfect nature, of little apparent value 

 to the angler or sportsman. 



