468 CLABKE AND DENTON [CHAP. 10 



Pumphrey, R. J., 1961. ' Concerning Vision ' from The Cell and the Organism. Essays pre- 

 sented to Sir James Gray. Cambridge Univ. Press. 



Russell, F. S., 1927. The vertical distribution of plankton in the sea. Biol. Revs. Cambridge 

 Phil. Soc, 2, 213-262. 



Russell, F. S. 1933. On the biology of Sagitta. Observations on the natural history of 

 Sagitta elegans Verrill and Sagitta setosa J. Muller in the Plymouth area. J. Mar. Biol. 

 Assoc. U.K., 18, 147-160. 



Southern, R. and A. C. Gardiner, 1932. The diurnal migrations of the Crustacea of the 

 plankton of Lough Derg. Proc. Roy. Irish Acad., B40, 121-159. 



Sweeney, B. M., F. T. Haxo and J. W. Hastings, 1959. Action spectra for two effects of 

 light on luminescence in Gonyaulax polyedra. J. gen. Physiol., 43, 285-299. 



Tyler, J. E., 1960. Radiance distribution as a function of depth in an underwater environ- 

 ment. Bull. Scripps Inst. Oceanog. Univ. Calif., 7, 363-412. 



Wald, G., 1945-6. The chemical evolution of vision. Harvey Lect., Ser. 41, 117-60. 



Wald, G., 1958. The significance of vertebrate metamorphosis. Science, 128, 1481-1490. 



Wald, G., P. K. Brown and P. S. Brown, 1957. Visual pigments and depths of habitat of 

 marine fishes. Nature, 180, 969-971. 



Waterman, T. H., 1958. Polarized light and plankton navigation. Perspectives in Marine 

 Biology. Ed. by A. A. Buzzati Traverso, 428-450. University of California Press. 



