Stbeam Pollution 41 



that fish vary widely in their resistance to pollution and in their 

 indifference to the presence of waste materials in the water. Most 

 of all, our valuable food fish are exceedingly sensitive, but some 

 other fish continue to live, if not to thrive, under conditions in which 

 certain sorts of pollution are very conspicuous. I include here a 

 table taken from Wells (1918) which gives knowledge on this point. 



