TABLE 2. — Comparison of Utermbhl and molecular filter methods 



""• Values from graphs in Holmes and Widrig (1956). 



SUMMARY 



Two modifications seem desirable in the 

 molecular filter technique of Goldberg, Baker, 

 and Fox (1952) for preparing marine nanno- 

 plankton for examination and enumeration. 

 These modifications involve the substitution of 

 alcoholic Fast Green for aqueous Fast Green 

 and of beechwood creosote or anisole for 

 cedar oil in the clearing process. 



A variety of phytoplankton may be readily 

 identified and counted on a filter disk, although 

 difficulties in identification have been en- 

 countered with the mu flagellates and a few 

 genera and species belonging to other plant 

 groups. 



Because the organisms are not distributed 

 randomly on the filter disk, all the organisms 

 should be counted. When the entire disk is 

 counted, the results are quantitatively com- 



parable with those obtained with the Uterm'ohl 

 (1931) technique. 



The technique is rapid and apparently pro- 

 duces a permanent preparation of the orga- 

 nisms; no signs of deterioration have been 

 observed in preparations 5 years old. 



LITERATURE CITED 



BALLANTINE, DOROTHY. 



1953. Comparison of the different methods 

 of estimating nannoplankton. Journal of 

 the Marine Biological Association of the 

 United Kingdom, vol. 32, no. 1, p. 129- 

 147, 



GOLDBERG, EDWARD D., MAJORIE BAKER 



and DENIS L. FOX. 



1952. Microfiltration in oceanographic re- 

 search. 1. Marine sampling with the 

 molecular filter. Journal of Marine 

 Research, vol. 11, no. 2, p. 194-204. 



