14 "THETIS " SCIENTIFIC RESULTS. 



•or the wind, and although passing a much less quantity of water 

 per minute, did good work. 



The tow-net was also occasionally run at night, and the phos- 

 phorescent or-ganisms, Copepoda, Sal2ja, etc., quite illuminated the 

 bottle in which they were received. Every ripple on the water 

 was also lighted with them, but not nearly so brilliantly as when 

 ■concentrated in the bottle of the tow-net. 



As the trawl was worked from the port side of the vessel, the 

 tow-net was necessarily run from the starboard. While watching 

 the trawl-warps small animals were often noticed floating by. 

 Many of these were obtained by dropping a caj^tive bucket over- 

 board. In this way I got examples of lanthina, and on one 

 •occasion, off Wata Mooli, at 5 p.m., March 12th, secured the only 

 three examples of Glaucus atlanticus observed during the cruise. 



PELAGIC LIFE. 



The harvest of the tow net greatly astonished all on board, to 

 whom pelagic life had an undreamed existence. When it was 

 further pointed out that these surface organisms were directly or 

 indirectly food for the fishes we were endeavouring to catch, those 

 specially interested in the trawling venture viewed the proceedings 

 with even keener attention. 



As so little is popularly known on this subject, and as it has 

 such great bearing on the fishing industry, I have been asked to 

 devote a paragraph to pelagic life. Until the gatherings of the 

 tow net have been systematically examined it is not possible to 

 detail the various captures. A very good idea of this pelagic life 

 may, however, be gleaned by pei-iodic visits to our ocean beaches. 



Working along the beaches in January, regular collectors note 

 the comparative absence of surface life. In February, under 

 suitable conditions, as the ripples recede from the sand, they leave 

 behind a line of minute animal life ; this pelagic life increases in 

 volume until about May, when it reaches its maximum. After 

 July this flux greatly diminishes. 



On scooping up a littleof this living line and placing it in a bottle 

 of water, it is seen to consist of a great variety and infinite 

 number of minute organisms. In greatest abundance are the 

 jelly-like bodies known as Sa/pa, members of the Tunicata, trans- 

 pai'ent and almost invisible, while in water, to the human eye. 

 Some of the larger species measure seven or eight inches in length 

 and weigh several ounces. Also common are species of worms, 

 Sagitta, likewise ti'ansparent. Scattered among these are many 

 different kinds of Crustacea such as Amphipods, allied to the 



