CHAPTER VII 



Internal Workings 



DIGESTIVE SYSTEM 



THE digestive system of a fish consists of a stomach and an 

 intestine, with a mouth at the front end for taking in nour- 

 ishment, and an anal opening at the rear end for disposing 

 of used food. In addition to these elements common to all 

 animals from the worm up, it has also some of the acces- 

 sories which we are apt to think of only in connection with 

 human beings, such as gall-bladder, spleen, and pancreas. 

 That it has a liver is not likely to be forgotten by those 

 who have had anything to do with cod-liver oil. 



The fish's mouth is full of teeth. It has teeth on its jaws, 

 and often on the roof of its mouth and on its tongue as well, 

 but it does not use these teeth to chew with. This fact was 

 borne in on me very clearly once when I found, in the stom- 

 ach of a trout I had just taken, several intact salmon eggs 

 of the preserved kind sold for bait. Either this fish had been 

 an expert at stealing bait off the hook without getting caught, 

 or some angler had dumped the remains of his egg supply 

 into the water. In any case, the eggs looked as good as new. 

 Out of curiosity I took one of them and put it on my own 

 line. In a very few minutes I had another trout on the bank, 

 and inside his stomach the same salmon tgg which his dead 

 brother had once eaten was still uninjured. Neither fish had 

 chewed it at all; at this rate a deft angler would need no 

 more than one salmon ^gg to carry him through a whole 

 season. 



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