no THE DRY-FLY MAN'S HANDBOOK 



more important still, keep trying other feeding fish. 

 The more often he hammers an individual trout, the 

 less likely he is to get a rise out of it. 



If, however, he should have the good fortune to 



land a trout, he can at times 



Autopsy. establish the identity of the 



insects on which it was feed- 

 ing by taking some of the insects out of its mouth. 

 If the mouth is empty and the fish undersized he is 

 again beaten, but if it should be sizable he may be 

 able to elucidate the question by means of an examina- 

 tion of the contents of its stomach. 



In the accompanying Plate IX is shown the longi- 

 tudinal section of a Test trout showing the air bladder, 

 pyloric appendages, and giving a good idea of the 

 digestive organs generally. A portion of the stomach 

 is cut open to show the undigested food it contains, 

 and below this a V-shaped valve called the sphincter 

 muscle, beyond which the undigested food does not 

 pass except as the result of some muscular exertion 

 required to excrete indigestible substances, such as 

 small stones or shells used by the caddis in making 

 its case. 



To perform an autopsy the best modus operandi is 

 to take the trout after killing it, and holding it with its 

 ventral side uppermost make a clean cut with a sharp 

 knife or pair of scissors from the vent up the centre of 

 the ventral surface to the pectoral fins. The whole 

 of the digestive organs can be turned out of the 

 slit, cut off close to the throat, and dropped into a 



