FLOTSAM AND JETSAM 211 



confined with almost equal rigidity by invisible 

 walls. Temperature, salinity, pressure and light are 

 some of the intangible and impassable frontiers. 

 But the study of these requires a maximum of dia- 

 grams and schedules which would be out of place 

 in this volume. Nevertheless, there is drama and 

 tragedy, plot and adventure, so let us consider sun- 

 light and darkness, or even light and shadow. I 

 have already told how the beings who love the sur- 

 face of the sea at night are all but absent from it in 

 the daylight, but many others are willing to come 

 up if they can find the merest excuse or parody of 

 a sheltering shadow. 



I will work up to concrete examples by a few 

 minutes' observation from the pulpit, which always 

 revealed the life and death need for even the slight- 

 est protection. The most faithful attendants of 

 the Arcturus were the tunny fish, who kept close 

 to the bow hour after hour, yielding to the occa- 

 sional dolphins but returning at once when they 

 had gone. Looking down through the ultramarine 

 film I saw a score of these fish metamorphosed to 

 rainbow colors — rich violet bodies with yellow 

 finlets and black tails. Now and then an unfortu- 

 nate flyingfish rose, then a tunny turned aside, 

 there was a flash in the air of molten silver and the 

 tunny was back. A few minutes later a dense mob 

 of several thousand half-beaks rose like hail. These 

 fish are on their way to becoming flyingfish, and, 

 sculling frantically with tail fins, skim through the 

 air, like planes near the end of their taxiing run. 

 Every tunny within sight flung itself headlong into 



