DEPARTMENT OF MARINE BIOLOGY. 



163 



Hence the water of shallow impounded tide-pools or reef-flats becomes 

 as alkaline as 8.6 Ph in sunlight, the normal ocean water being 8.2 Ph- 

 Only nine investigators studied under the auspices of the Depart- 

 ment during the year, for war conditions and the uncertainty of our 

 plans for the future rendered it undesirable to invite new men to com- 

 mence studies at Tortugas; thus only those who had previously 

 worked at Tortugas returned to extend or complete their researches. 

 The following is a list of the investigators thus employed : 



In response to requests from President Woodward, Mr. G. R. 

 Putnam, Commissioner of the U. S. Bureau of Lighthouses, granted 

 a permit to Professor S. C. Ball to remain for one month at Rebecca 

 Shoal Lighthouse in order that he might study the migrations of mos- 

 quitoes. Later, also, he granted permission to Professor W. H. Longley 

 to land upon East Key in order to facilitate his study of the coloration 

 of fishes. 



