ANIMALS OF NO IMPORTANCE. 



called the Nekton ; and the smaller organisms whose nata- 

 tory powers are but small, and which are at the mercy of 

 the waves, being carried about hither and thither by wind 

 and current. This group, which includes jelly-fish and 

 small crustaceans, is often termed the Plankton. The 

 Nekton are disturbed by the approach of the-ship and hurry 

 away from it, and thus mostly elude the observer's gaze. 

 Most of the Plankton, on the other hand, are so small as to 

 be invisible to the naked eye ; and the majority of them 

 come to the surface only at night, descending some feet as 

 soon as daylight approaches. The object of this daily mi- 

 gration is to enable these lowly organisms to make the most 

 of the light. This habit of descending during the day 

 allows them to search for food, both by day and by night. 

 Were they to remain at the surface during the day, they 

 would lose their only chance of obtaining food at a greater 

 depth. 



Of the remaining Plankton others are almost transparent, 

 so that it is most difficult to see them when the sea is at all 

 rough. But give him one of those heavenly days, so few 

 and far between, such as March 6th, 1900, when the sea 

 was as smooth as glass, and the naturalist desires nothing 

 more. He has ample opportunity of studying marine life. 

 But he must go right forward to the bow of the ship, where 

 he can look down into the blue water as yet undisturbed by 

 the rude contact of the fast-moving steamer. Magnificent 

 jelly-fish may be seen in thousands, some almost perfectly 

 transparent, others of a milky-white hue with pink patches. 

 They float near the surface, moving most gracefully by the 

 rhythmic contraction of their "bell " or "umbrella." There 

 is no more beautiful sight in nature than the movement of a 

 medusa. Dozens of other Plankton may be seen on such a 

 day, creatures of diverse form and size, displaying the most 

 beautiful tints : deep red, orange, pink, brown, yellow, and 

 blue. In half an hour the writer noticed no fewer than 

 eleven different genera of such organisms Medusa 

 Siphonophora, and Ctenophora. 



