THE TEEMING LIFE OF THE WATERS 



If I turn over the pages of my old notebooks and 

 sketchbooks I find the shapes and forms of these 

 creatures for which I have often fished, though fisher- 

 men of the usual type know nothing of them. I dis- 

 cover impressions, remarks, like those of other naturalists 

 who like myself have fished for the same catch. These 

 planktonic creatures belong to many of the groups of 

 marine life. Animal and vege- 

 table kingdoms are represented 

 in them, though unequally, 

 for animals predominate as re- 

 gards mass, diversity, and com- 

 plexity, often by size too. 



The vegetables have a less 

 obvious part. They are almost 

 entirely limited to Protophyta, 

 which are unicellular plants, 

 elementary in structure and 

 microscopic in size. Their 

 principal groups are those of 

 the Blue-green Seaweeds and 

 Diatoms and the Dinoflagellates 

 The Blue - green Seaweeds, 

 closely related to the Bacteria, 

 are among the tiniest and most 

 elementary of all beings en- 

 dowed with life. Their sub- 

 stance, devoid of any nucleus, 

 or composed of diffuse and granulated nuclear matter 

 only, is sometimes colourless, sometimes tinted with a 

 greenish-blue pigment, phycocyanine, which permeates 

 it sometimes in association with chlorophyll, the green 

 colouring matter of plants. The Diatoms and Dino- 

 flagellates are beings of a higher order, despite their 

 smallness and rudimentary organisation. They have 

 a complete cellular structure, often containing chloro- 

 phyll; their tiny bodies are surrounded by a strong 

 envelope, a thin piece of cell wall often regular and 



7 



Fig. 2. — Floating larva of an 

 annulate sea-water worm, 

 known as the Sea Mouse, 

 belonging to the genus Poly- 

 noe. The adult lives on the 

 bottom ; its larva, one or 

 two millimetres in length, 

 forms a part of the plank- 

 ton carried along by the 

 currents. 



