48 MARVELS OF FISH LIFE 



how environment and food supply have so greatly- 

 altered this fish in size, shape and markings as to make 

 him appear in the guise of the migratory salmonoid, 

 the Great Lake trout, the gillaroo and others. 



The brown trout is to be found in waters of very 

 varied description. He may have to dart after every 

 particle of food and passing fly in a barren Highland 

 burn, or he may be able to pick and choose his food in 

 a lake teeming with insect life. Whichever is the case, 

 when the autumn arrives instinct tells him that there 

 are other duties in life besides feeding, and so he gradu- 

 ally makes his way to the spawning beds upon which the 

 eggs are deposited. 



After the summer droughts the water is probably low, 

 and the trout is prevented from getting to the gravelly 

 bed he knows so well, and with many others is compelled 

 to wait in the first deep pool for the autumn rain. Here 

 he may meet a mate, and subsequently they may travel 

 together to the spawning ground. More often than not 

 he waits until he reaches his destination before selecting 

 a bride. 



At last the rain descends, the river comes down in 

 flood, and the pool which the day before held many 

 waiting fish is now uninhabited. Trout racing through 

 the rapids and resting for a time in the pools, gradually 

 make their way to the very source of the stream, where 

 the sparkling water gurgles over the gravelly beds. Here 

 the male and female fish carefully select a suitable spot. 

 The female then deposits her eggs, which are fertilised 



