LIFE ON THE OCEAN SURFACE. 567 



On the voyage from Ternate to the Philippine Islands, the 

 sea was again seen to be full of minute algae. In this case there 

 were several other forms beside Trichodesmium, and they were 

 embedded together in small masses of a jelly-like substance, 

 which also contained Diatoms. The water was perfectly full of 

 these masses, and tinted by them of a light brownish colour. 



Besides these smaller algae living in the open ocean, there are 

 abundance of several species of larger seaweeds which are 

 Pelagic in habit. The Gulf Weed, Sargasmm bacciferum, of the 

 Sargasso Sea in the Atlantic, is well-known. It is brown when 

 dried or preserved, but when living is of a very bright yellow 

 colour, which contrasts pleasingly with the deep blue of the 

 open Atlantic. Another seaweed (Fucus vesimlosus) is to be 

 found also living free in the Atlantic, and the Giant Kelp 

 (Macrocystispirifera), in the floating condition, ranges over a wide 

 belt of the Southern Ocean, as proved by Sir Joseph Hooker* 



All these seaweeds grow attached to rocks on various shores 

 as well as free, but they all produce spores, only when attached. 

 The Pelagic varieties multiply only by simple growth and sub- 

 division. A wide area covered with seaweeds corresponding to 

 the Sargasso Sea occurs in the North Pacific Ocean. 



Were it not for the existence of this vast Pelagic vegetation 

 the Pelagic fauna would be but a scanty one, since the debris 

 derived from the land could only support a small amount of 

 animals. Plants are as necessary in the open sea as on land to 

 form the starting-point of the organic cycle by building up those 

 compounds required by animals as food. The algae, though brown 

 in appearance, contain and build up Chlorophyll, the same green 

 colouring matter as that which tinges the leaves of our trees and 

 plants on land, and which is now the only starting-point and 

 foundation-stone of life. 



The Sargasso Sea has its own fauna of animals specially 

 adapted to life amongst the Gulf Weed. Amongst these there is 

 a small fish, Antennarms, allied to the Angler, which has long 

 arm-like fore-fins with which it clings on to the bunches of 

 Weed. The fish makes a nest of the Weed, binding together a 

 globular mass of it, as big as a Dutch cheese, by means of long 

 * " Flora Antarctica," Vol. I, pp. 464-465. 



