[Chap. XLVII THE ALGAE 637 



of branches and carpospores, which superficially resembles a fruiting 

 body, is called a cystocarp. When a carpospore becomes free and 

 germinates, a new Nemalion plant develops from it. Reduction division 

 occurs during the formation of the carpospores. 



The ordinary Nemalion plant, therefore, is the gametophyte phase 

 with the monoploid number of chromosomes. The short branches of the 

 cystocarp that developed from the fertilized egg have the diploid num- 

 ber of chromosomes and constitute the sporophvte { carposporophyte ) 

 phase in the life cycle of Nemalion. 



Batrachospermum and Lemanea. The fresh-water Batrachospermum 

 grows on the rocks in riffles and waterfalls in streams and in the wave- 

 disturbed margins of lakes of the temperate zone. It has whorls of short 

 branches at the nodes of a central axis, all enclosed in a heavv mucilasi- 

 nous sheath. The color varies from bluish green to violet. Its life cvcle 

 is similar to that of Nemalion. Another common relative in rapidlv flowing 

 streams is Lemanea. The filaments of some species when magnified look 

 like bamboo rods. The life cycles of these plants are more complicated 

 than that of Nemalion, but they are not as complex as those of many 

 other red algae. 



REFERENCES 



Brown, William H. Tltc Plant Kingdom. Ginn & Company. 1935. 



Conger, Paul S. Origin and utilization of diatomaceous peat deposits. Sci. 



Monthly 49:509-523. 1939. 

 Fritsch, F. E. The Structure and Reproduction of the Algae. \'ol. I. Macmillan 



Company. 1935. 

 Hall, R. P. The trophic nature of the plant-like flagellates. Quart. Rev. Riol. 



14:1-12. 1939. 

 Kudo, R. R. Protozoology. C. C. Thomas, Publisher. 1939. 

 Smith, G. M. Cryptogamic Rotamj. Vol. I. Algae and Fungi. McGraw-Hill 



Book Company, Inc. 1938. 

 Smith, G. M. Freshwater Algae of the United States. McGraw-Hill Book Com- 

 pany, Inc. 1933. 

 Taylor, W. R. Marine Algae of the Northeastern Coast of North America. 



Univ. of Michigan Press. 1937. 

 Tiffany, L. H. Algae, the Grass of Mam/ Waters. C. C. Thomas, Publisher. 



1938. 

 Tilden, J. E. The Algae and Their Life Relationships. Univ. of Minnesota 



Press. 1935. 

 Tressler, D. K. Marine Products of Commerce. Chemical Catalogue Companv. 



1923. 



