FLOTSAM AND JETSAM 213 



if it failed to sink there would soon be a small 

 fish swimming close beneath it. I could imagine 

 the widening cone of shadow which the can cast 

 downward and the fish, feeling its comfortable 

 darkness, followed it up until it focussed on the 

 bobbing bit of floating tin. 



In calm sunny weather as the Arcturus steamed 

 along at full speed, few or no fish were to be seen 

 in the open water. Then "full stop" would clang 

 when I decided to sound or take temperatures and 

 soon after we began to float quietly, on the shady 

 side, fish, small crabs and other creatures would 

 begin to collect, coming up from deeper levels into 

 this premature twilight. These, however, were only 

 the skirmishers on the edge of the great nocturnal 

 host — that vast army who could never be fooled by 

 an artificial night and who kept far down below 

 the twilight zone, waiting for the blotting out of the 

 sun before they began their upward rush. I had 

 read of this interesting vertical migration before I 

 started on the Arcturus and the contents of every 

 net proved its magnitude. But not until I inaug- 

 urated a series of twenty-four-hour surface hauls, 

 taken at fifteen minute or half hour intervals, did 

 I appreciate the clock-like regularity of the move- 

 ment. After a little practice, I knew that if I 

 wanted a certain type of nocturnal surface fish, a 

 haul at 4.15 to 4.30 a. m. would invariably capture 

 some, while the net drawn from 4.45 to 5 o'clock 

 would never contain a single one. 



At Station Seventy-four, I made twenty-four 

 hauls in as many successive hours and took over 



