156 ANIMAL LIFE UNDER WATER 



of the head. This causes a suck, and the fly is 

 carried down into the mouth of the trout. 



When the fish is a foot or two below the 

 surface, he behaves in two ways. He may come 

 up to inspect the fly before he takes it, in which 

 ease he feeds as described. On the other hand, 

 the trout may make up his mind that he will have 

 the fly before he starts. Under these circum- 

 stances he rushes at it open-mouthed. When a 

 fish feeds in this manner there is often a loud 

 splash, and the fly is missed, because it is knocked 

 out of the way. When food is taken under the 

 water, the gorged fish may come leisurely 

 towards it, but the feeding fish rushes at it with 

 open mouth. The mouth of a trout in these 

 circumstances is often open when the fish is still 

 two to three feet from the food. 



On the plate opposite are three photographs. 

 In the top one, the trout has detected food, and 

 is giving a lateral swish with its tail to drive him 

 through the water. In the two lower illustra- 

 tions the same fish is shown moving rapidly 

 forwards with the mouth open. 



When these photographs were taken the food 

 was thrown into the water about six feet in front 

 of the trout, and the mouth was invariably open 



