464 General Botany 



Corallines, which are often associated with the true corals on the 

 coral reefs of the tropics, and a few species of which extend into 

 cold waters. 



The spores and sperms of the red algae are without cilia and are 

 not motile. The egg cell is inclosed and stationary. Their 

 methods of reproduction and their life histories are highly com- 

 plicated and cannot be detailed here. 



Economic importance. The common " dulse " and Irish 

 moss of northern coasts are used in the production of blanc- 

 mange and jellies. In Asia several species of red algas, together 

 with a few species of brown algas, are used in the making of agar, 

 which is in composition a complex of gelatinous carbohydrates. 

 In Japan the red algae are not only collected, dried, and used 

 as food in enormous quantities, but the algae are actually culti- 

 vated in shallow arms of the sea. The edible bird's-nest of the 

 Orient is constructed of seaweeds. 



REFERENCES 



Collins, F. S. Green Algce of North America (3 Supplements). Tufts College 



Library, Medford, Massachusetts; 1918. 

 TiLDEN, J. E. MyxophycecB of North America. Minnesota Biological Survey; 



1910. 

 Ward, H. B., and Whipple, G. C. Freshwater Biology. John Wiley & Sons, 



Inc., New York; 1918. 

 West, G. S. Alga. G. P. Putnam's Sons, New York; 1916. 

 Treatise on British Freshwater Algce. G. P. Putnam's Sons, New York; 1904. 



