38 Marine Microbiology 



the papers have one thing in common. They point out the en- 

 thusiasm of marine microbiologists throughout the world, and the 

 paucity of our knowledge. Every paper, though it denotes im- 

 portant progress, finished by raising questions rather than an- 

 swering them. 



Such questions are;— 



1. How do we explain the existence of large quantities of 

 phytoplankton organisms at depths far below the photic zone, 

 whence do they derive their energy and what is their carbon 

 source? 



2. What is the actual importance of heterotrophy in phyto- 

 plankton organisms within the photic zone? 



3. Do we know enough of the biology of phytoplankton to 

 supply factors for dark fixation of carbon, reproductive and 

 grazing rates and other biological data in the productivity equa- 

 tion? 



4. What are the factors governing the succession of phyto- 

 plankton, the occurrence of monospecific and polyspecific blooms 

 in oceanic waters and what promotes or limits phytoplankton 

 populations? 



5. What is the significance of fungi, yeasts and viruses in the 

 oceans? 



These are only a few of the questions that arise in our minds 

 when we read the papers given in my session. You will tliink of 

 many more. 



All our speakers show an increasing awareness of the com- 

 plexity of our problems and a determination to proceed towards 

 a solution of them. It is not long since there were only one or 

 two voices crying in the wilderness of marine microbiology, par- 

 ticularly those of Waksman and ZoBell, and it is only very 

 recently that it has been recognized as a discipline which should 

 have support and in which one could profitably work, and in 

 fact maintain as a life-work. I can only hope that this symposium 

 will stimulate the interest of microbiologists in general, and speed 

 up the tempo of research in this absorbing subject. Now that 

 we have enthusiastic workers, especially among the younger gen- 

 eration, we need only the facilities to extend our research. These 

 facilities include still more enthusiastic people, and also finance 



