TROUT IX S.A. WATERS 271 



Brown trout small chance of existence. It is noticealbe 

 in some seasons how trout rise freely for some time and 

 then suddenly stop altogether for the rest of the season. 

 This is probably due to the production of some form of 

 bottom food in large quantities. It can be easily proved 

 by frequent autopsies and if the habit becomes general 

 and incessant the only remedy is to increase the stock 

 of fish and thus, by the exhaustion of the bottom source 

 of food supply, induce surface feeding. 



The temperature of our river waters has a very im- 

 portant bearing on the fish and plant life. The highest 

 water temperature ever experienced by the author was 

 at Ceres, being So" Fahrenheit in still water at the sur- 

 face and 82" in running water. Xeedless to say no fish 

 could survive such a temperature and as no dead ones 

 could be found it is presumed they sought cooler water at 

 the bottom of deep pools or migrated to the cooler head 

 waters. On lOth January, 1917. in the weir pool at Ver- 

 genoeg (Faure). I found the surface water temperature 

 to be SO' Fahr. and saw six trout from two to three 

 pounds and twenty ranging from 12" to 9" long on the 

 move, to and fro. in the pool below the weir. Above the 

 weir boards about 12 trouts running from 14" to 9" long 

 were hanging against the upstream side of the boards 

 with the water passing over them. As I stood in the 

 water on the weir, on the upstream side of the boards, 

 many fish passed and re-passed within a few inches of my 

 legs, without apparently noticing my presence. They all 

 seemed languid though restless. Two swam into shallow 

 water so near to me that I could have taken them in 

 my landing net or kicked them out of the water. Later 

 on some rubbed against my legs and continued doing so 

 until I moved, when they swam slowly away. Some had 

 their backs out of the water, others moved listlessly about 

 among the reeds on the bank. Many were Brown trout 

 and they varied very much in colour. Two appeared to 

 have fungoidal growths on their backs. On the whole the 



