HOW TO KNOW THE SEAWEEDS 



ously varied life histories and often exceedingly complex reproductive 

 mechanisms. So varied are these that space is available here only 

 for the presentation of a few generalizations and examples under 

 each of the three major seaweed divisions. For more detailed infor- 

 mation the student is referred to G. M. Smith's Cryptogamic Botany, 

 Vol. 1, McGraw Hill & Co., and for a highly comprehensive account 

 with full bibhography, to F. E. Fritsch's The Structure and Reproduc- 

 tion of the Algae, Volumes 1-2, Cambridge University Press. 



THE GREEN ALGAE 



Only about 10% of the Chlorophyta are marine, but among these 

 a number of different orders are represented along with a consider- 

 able range in reproductive complexity. Both asexual and sexual repro- 

 duction occur. In some of the simpler filamentous forms reproduction 



sporophyic 

 plan 



^oospores 



iion 



germination 



ga,metophyie 

 plants 



C/ gametes 



Fig. 9. Diagram of the Life Cycle of L//va. 



20 



