THE OPEN SEA 69 



the circulation of matter, we must always be- 

 gin with the plants. 



In most parts of the sea, wherever the sun- 

 light penetrates and the temperature is not too 

 low, there are countless myriads of simple 

 plants, " scattered like dust amid the immeas- 

 urable water masses." These minute marine 

 Algae are not visible to the naked eye, and it 

 is only within comparatively recent times that 

 their abundance, and their great importance 

 in the chain of life in the ocean, have been 

 fully recognised. Between Australia and New 

 Zealand, we are told, the officers of the Chal- 

 lenger, the ship of the great ocean expedition 

 sent out by the British Government in 1873- 

 1876, found the water "continuously discol- 

 oured during a period of several days' sailing, 

 and giving off the odour of a reedy pond." 

 Elsewhere too, even in the Arctic Regions, 

 the water is sometimes " as thick as soup." 



Along with the minute Algae there are many 

 minute animals (Infusorians) which have got 

 possession of the green pigment chlorophyll, 

 and there are others (Radiolarians) which 

 have Algae living in partnership with them. 

 All these form part of the fundamental food- 

 supply of the open sea. They are eaten by 



