MISCELLANEOUS OBSERVATIONS 161 



nature of their surroundings. In addition, trout 

 show certain "fear markings" which are not 

 dependent upon light. When a trout is alarmed 

 it rushes of? to hide itself in some dark corner. 

 Should this dark corner be available, the fish is 

 soon lost to sight, but if the fish has to take 

 shelter in light surroundings, the body of the 

 trout reflects the colour around, except for a 

 dark band down each side of the body and four 

 irregular prolongations from this band towards 

 the back. These dark markings give the fish a 

 blotchy appearance, which are well illustrated in 

 the colour photograph of the common brown 

 trout which serves as the frontispiece to this 

 volume. 



If the alarmed trout is further disturbed, it 

 will dash away, and as it rushes through the water 

 the fish has a distinctly barred appearance. 

 After swimming about for a few minutes, these 

 dark marks disappear, and the fish becomes a 

 uniform shade. When the trout comes to rest it 

 is still of a uniform shade, but, if again alarmed, 

 the blotchy appearance will return within a few 

 seconds. The barred appearance of the fish as 

 it swims away has no connection with the primi- 

 tive parr marks of the trout. 



