DEVELOPMENT OF PLANTS 



199 



Class C. Red Algae or Rhodophyceae 



74. General Features. — The Red Algae are largely marine 

 plants. Unlike the brown algae, they reach their greatest de- 

 velopment and abundance in the warmer waters of the temperate 

 and tropical seas and are usually found attached to various ob- 

 jects below tidal marks. Their red pigments probably adapt 

 them to the feeble illumination of the deep waters in which they 

 generally occur. They range through a great variety of forms, 

 from delicate filaments or flattened ribbon-like bodies to struc- 

 tures with cylindrical axes and leaf-like branches (Fig. 125). 

 The elegant symmetry of their branching together with the deli- 



-■3' -.'i^'i'iN vM 



Fig. 125. Common forms of the Red Algae: A, a leaf-like form, Deles- 

 seria. B, a branching thread-like form, Ceramium. C, a branching form 

 covered with delicate hairs, Dasya. 



cacy of structure and richness of coloration has always attracted 

 attention and made them the most familiar of all the algae. 

 They are popularly though inaccurately known as sea mosses. 

 Reproduction of the Red Algae. — The reproduction of the 

 Rhodophyceae, particularly the sexual method, presents so many 

 modifications and specializations that only the general features 



