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THE SEAWEED RESOURCES OF 

 NORTH CAROLINA 



BY Harold J. Humm. 



Duke University Marine Laboratory * 



Introduction 



Brown Algae 



Red Algae 



Chemical Nature and Physical 



Properties of Agar 

 Uses of Agar 



The Agar Industry of California 

 The Agar Industry of North 



Carolina 



INTRODUCTION 



Seaweeds or marine algae constitute several major groups (phyla) of plants 

 that are the oldest on earth. It is believed that the ancestors of our modern 

 seaweeds developed in oceans ages ago, probably before conditions on land 

 permitted development of plants as we know them today. Seaweeds, which 

 differ radically from land plants in structure and reproduction, are regarded 

 as primitive in these respects. 



The four major groups of seaweeds are commonly known as bluegreens, 

 greens, reds, and browns. The classification is based in part on pigmenta- 

 tion, but the gross color of seaweeds is not always a reliable character for 

 determining the proper phylum. The red algae are particularly variable. 

 Although all red algae contain a red pigment in addition to chlorophyll 

 (green), they are sometimes green or brown in color because the red pigment 

 may be masked by chlorophyll or other pigments. 



Marine algae, like all land plants having green leaves, must have light 



* Later, Marine Biological Laboratory, Florida State University. 



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