CONTENTS 



Introduction page 3 



General hydrological features 3 



The economic importance of the phytoplankton 11 



Acknowledgments 12 



Material 13 



Methods 14 



The main types of phytoplankton met with in the South Atlantic ... 19 



The phytoplankton of Antarctic surface waters 20 



The phytoplankton of sub-Antarctic surface waters 22 



The phytoplankton of sub-tropical surface water 25 



The phytoplankton of tropical surface water 26 



Summary 27 



The phytoplankton of the South Georgia area 29 



The plankton survey of January-February 1930 29 



The plankton survey of November 1930 41 



Other material 63 



Conclusions 65 



Comparison with the results obtained in 1926-7 65 



The probable seasonal succession 68 



The transition from Antarctic to sub-Antarctic phytoplankton .... 69 



The season 1929-30 71 



The season 1930-1 80 



The phytoplankton of the Weddell Sea area 88 



The season 1929-30 88 



The season 1930-1 90 



Conclusions 106 



The phytoplankton of Bransfield Strait 109 



The survey of February 1929 109 



The survey of November 1929 116 



The survey of December 1930 126 



Conclusions 134 



The phytoplankton of the Bellingshausen Sea 136 



The season 1929-30 136 



The season 1930-1 143 



Conclusions 152 



Notes on the species 153 



General conclusions 175 



Summary of observations 175 



The floras of the main types of water 177 



The probable seasonal succession 178 



Areas of local concentration 181 



Comparison of the fertility of the different areas 182 



The possible limiting factors 183 



Chemical factors 183 



Physical factors 186 



List of literature 195 



Appendix I. On factors limiting phytoplankton production in East Cumber- 

 land Bay, South Georgia 199 



Appendix II. Tables I-LV 217 



