FEBRUARY 39 



in fishculture and in the management of 

 waters, shows how knowledge is progress- 

 ing. The trout-fishing in a certain lake, 

 Mr. Armistead tells us, had been steadily 

 falling off from year to year. There 

 was no obvious explanation. The lake 

 was not polluted ; it was not overfished 

 by legitimate anglers ; poachers did not 

 harry it in any exceptional measure. 

 What was the cause of the decline ? 

 Was it that, while plentiful as ever, the 

 fish were gradually ceasing to rise ? It 

 would be well, Mr. Armistead thought, 

 to know what stock the water held. To 

 gain this information, he built a trap at 

 the mouth of the stream which feeds the 

 lake. "Every fish leaving the lake to 

 spawn was caught, and the amazing fact 

 revealed that the proportion of males to 

 females was only one in seventeen." This, 

 of course, meant that the stock had been 

 declining, and that it must for a time 

 continue to decline. It is not known that 

 trout are ever polygamous ; if any of them 

 are, it is certain that the departures from 



