App. E. Poisoning of rivers. 279 



together, and in the height of the hot season, of a few 



inches only in depth, under a tropical sun. Their depths 



afford also concealment, and probably greater facilities 



for escape from otters. To bottom feeders, which the 



large fish mainly are, they must also yield more food 



than the shallows. They are natural 

 Paras. 51, 52. . . , ,, 



resting places for the spawners, as 



shown below. 



12. These pools are well known to the villagers, are 

 all distinguished by local names, and are selected as the 

 ones for poisoning; consequently the poisoning of one of 

 these pools is pretty nearly equivalent, as far as the big- 

 ger sorts of fish are concerned, to the poisoning of four 

 or five miles of river. 



13. Thus whatever may be the cause of larger sorts 

 of fish congregating in the deepest pools, the fact remains 

 that they do so, and that it is taken advantage of for 



their poisoning. It may also be taken 

 advantage of for their protection. 



14. But the chief sources of most of the Canara 

 rivers are on the western ghats of Mysore and Coorg, 

 and to these it is that the best fish migrate for spawn- 

 ing purposes. Efforts to stop poisoning, and to protect 

 the fry, must therefore be incomplete, till the same meas- 

 ures are adopted in Mysore and Coorg. It is obvious that, 

 to be treated successfully, the rivers must be treated as 

 a whole, no matter what territory they run through. It 

 may seem unreasonable to object to the Coorgs and My- 

 .soreans destroying the fish within their own countries; 



